INTERNATIONAL UNION OF CRYSTALLOGRAPHY

EIGHTEENTH GENERAL ASSEMBLY

By-Law 1.7 requires that, unless decided otherwise by the General Assembly, matters concerning adherence to the Union shall take precedence over all other business at the first business session of the General Assembly.

There are no proposals to amend the Statutes and By-Laws in matters affecting adherence to the Union.

At the time of preparing these papers, no applications for membership of the Union have been received.

The Chair of FOMRE and the Chair of NVK (the Dutch Association for Crystallography) have formally requested that NVK replace FOMRE as the Adhering Body for the Netherlands. The Royal Dutch Academy of Science would continue to pay the membership fees for NVK in Category II, as it had done for FOMRE.

NVK has formed a National Committee for Crystallography [D. Feil (Chair), J.L. de Boer, C.Th. Kiers, J. Kroon, R. Olthof-Hazekamp (Secretary), D. Reefman, F. Tuinstra].

The Executive Committee recommends to the General Assembly that the new Adhering Body for The Netherlands should be the NVK.

The Royal Society has given formal notice that it will cease adherence to the IUCr at the Glasgow Congress. The Royal Society recommends that the British Crystallographic Association (BCA) should become the new Adhering Body for the UK.

The President of the BCA has confirmed that the BCA agrees to become the Adhering Body and pay the subscription in Category V.

The membership of the National Committee would remain unchanged [A.M. Glazer (Chair), F.H. Allen, P. Barnes, A.J. Blake, R.L. Brady, K.M. Crennell, C.J. Gilmore, S. Harris, D.G. Hart, J.A.K. Howard, J.A. Jutson,

S.J. Maginn, H. Muirhead, P.A. Thomas, C.C. Wilson, M.M. Woolfson].

The Executive Committee recommends to the General Assembly that the new Adhering Body for the UK should be the BCA.

The Minutes of the Assembly are contained in the Report of the Seventeenth General Assembly and International Congress of Crystallography published in the September 1997 issue of Acta Crystallographica Section A [Acta Cryst. (1997). A53, 692—748]. Reprints of this Report were sent to the Secretaries of all National Committees for Crystallography, the Chairs and Secretaries of IUCr Commissions and IUCr Representatives on other bodies in November 1997.

The Executive Committee proposes that the General Assembly amends the Statutes and By-Laws to make them non-gender-specific by changing 'he' to 'he or she' etc., or by appropriate re-wording, and by changing 'chairman' to 'chair'. A draft version of the Statutes and By-Laws that incorporated these changes (and also the change of name of ICSU to International Council for Science) was circulated to the National Committees and Commissions in April 1999.

The Executive Committee met in Seattle in August 1996 before and during the General Assembly, in Lisbon, Portugal, in August 1997 at the time of the Seventeenth European Crystallographic Meeting and in Arlington, USA, in July 1998 at the time of the American Crystallographic Association annual meeting. The Finance Committee met in March 1996, August 1996, March 1997, August 1997, March 1998 and July 1998, to prepare its advice and recommendations on finances, establishment and staff matters.

The most important items of business dealt with by the Executive Committee during the triennium at these meetings, and in postal ballots between meetings, were:

(1) editorial policy, pricing policy and subscription rates, consideration of appointment of new Editors for Acta Cryst. Section C and the Journal of Applied Crystallography, approval of appointments of Co-editors, electronic publishing, Special Issues, format of offprints, and other matters concerning the IUCr journals;

(2) appointment of a Promotions Representative;

(3) approval of the audited accounts for the previous year;

(4) the General Fund estimates and the level of the unit contribution;

(5) investment policy;

(6) funding and uses of the Publications and Journals Development Fund and the Research and Education Fund;

(7) sponsorship and financial support for meetings, including young scientists' support;

(8) cooperation with databases, including relations between the IUCr and the Cambridge Crystallographic Data Centre and between the IUCr and the Fachinformationszentrum Karlsruhe;

(9) progress with Volumes A, A1 (formerly H), B, C, D, E, F and G of International Tables and development of associated software, consideration of suggestions for new volumes;

(10) the IUCr Newsletter, the Tenth Edition of the World Directory of Crystallographers;

(11) fiftieth anniversary of the IUCr;

(12) appointment of the Selection Committee for the fifth Ewald Prize;

(13) discussion of the arrangements for the Glasgow General Assembly and Congress;

(14) approval of the membership of the Programme Committee for the Glasgow Congress;

(15) level of financial support for the Glasgow Congress;

(16) importance of crystallography;

(17) nominations for Officers of the IUCr and for Chairs and members of Commissions, and proposals from the National Committees for these positions.

Other items dealt with in this way were:

(18) consideration of a proposal to establish an Inter-Union Bioinformatics Group;

(19) the implementation of the Crystallographic Information File (CIF) for Acta Crystallographica and other uses of CIF, patent application and adoption of the STAR file and CIF by other bodies, work of the Committee for the Maintenance of the CIF Standard (COMCIFS), provision of checking services to other publishers;

(20) approval of publications, jointly with Oxford University Press, in the IUCr/OUP Book Series;

(21) charges for visas;

(22) crystallography in Africa;

(23) use of financial support through ICSU;

(24) access to large-scale research facilities;

(25) review of the activities of Commissions;

(26) review of the activities of Regional Associates;

(27) review of the reports of IUCr Representatives on other bodies.

Items concerning the Chester office were:

(28) staffing requirements in the IUCr office in Chester;

(29) upgrading of office technology in the IUCr office in Chester, provision of Internet services, domain site name, formation of an IUCr web editorial board, and establishment of mirror sites.

The subscription prices (in Danish Kroner) of Acta Crystallographica, the Journal of Applied Crystallography and the Journal of Synchrotron Radiation were increased each year during the triennium.

The total annual number of pages published in 1996, 1997 and 1998 were:

In addition, in 1996 Acta Cryst. Section A included a Supplement of 688 pages of abstracts communicated to the Seattle Congress.

The November 1998 issue (Part 6, Number 1) of Acta Cryst. Section A was a celebration of 50 years of Acta Crystallographica and the IUCr, edited by H. Schenk. It contained 269 pages of 26 invited papers presenting state-of-the-art research from sciences in which crystallography has played a major role. The first paper was 'Aspects of the History of the International Union of Crystallography' by D.W.J. Cruickshank. This issue of Acta Cryst. was also published as a book entitled Crystallography Across the Sciences.

The October 1997 issue (Part 5, Number 2) of JAC contained 320 pages of papers presented at the Tenth International Conference on Small-Angle Scattering, Campinas, Brazil, 21—26 July 1996. The November 1998 issue (Part 6, Number 1) of Acta Cryst. Section D contained 142 pages of 'Databases for Macromolecular Crystallographers', the Proceedings of the CCP4 Study Weekend, Reading, UK, January 1998. The May 1998 issue of JSR contained 1,054 pages of papers presented at the Sixth International Conference on Synchrotron Radiation Instrumentation SRI '97, Himeji, Japan, 4—8 August 1997.

Submission of papers to Acta Cryst. Section C in fully electronic CIF format is complete and automatic data validation software and CIF-access electronic-only publication have been introduced. The other journals are now produced in SGML format ready for on-line publication.

The IUCr home page on the web continues to expand and the main site in Chester, UK, is currently mirrored in France, Israel, South Africa, Sweden, Switzerland and the USA. It contains information in the following categories: The Union and its Components (including information on Adhering Bodies, Commissions, Regional Associates, Annual Reports, Congress Reports, etc.); Journals and Other Publications (including information on the titles, synopses, structural schemes and contents of the IUCr journals); and Services (including the World Database of Crystallographers). The number of requests per day is typically of the order of 10,000.

Full details on the publication of volumes of International Tables for Crystallography are given in the Triennial Report of this Commission (Appendix 11 to the Agenda).

The Tenth Edition of the World Directory of Crystallographers, edited by Y. Epelboin, was published in 1997. This is held as an electronic database in STAR file format and this also allows the automated typesetting of the Directory. The database may be accessed via the web.

The IUCr/OUP Book Series continues to be successful. Details are given in Appendix 15 to the Agenda.

The IUCr Newsletter is distributed free of charge to 587 libraries and 15,000 crystallographers and other interested individuals in 39 countries. W.L. Duax is the Editor with the editorial office at the Hauptman—Woodward Medical Research Institute at Buffalo, New York, USA, which also handles the distribution. A report on the IUCr Newsletter is given in Appendix 14 to the Agenda.

The Executive Committee has established a Sub-committee on the Union Calendar to consider and to advise the Executive Committee on requests for IUCr sponsorship and financial support of meetings. The Chair of the Sub-committee has been H. Schenk in this triennium. A list of IUCr-sponsored meetings is given in Appendix 26 to the Agenda.

Applications for sponsorship and financial support are considered if they are submitted at least nine months in advance of the date of the meeting. Requests from satellite meetings must be submitted, and possible financial support requested, through the organising committee of the main meeting. Meetings (other than satellite meetings) scheduled to be held within two months before or after an IUCr Congress will not be considered for sponsorship. For any meetings scheduled to be held between two and three months before or after a Congress, the application for sponsorship requires the approval of the Chair of the Congress Programme Committee.

The IUCr continues to support and uphold ICSU's policy of non-discrimination and adheres to its decisions and procedures concerning free circulation of scientists. Organisers of any meetings seeking IUCr sponsorship or support must assure the Calendar Sub-committee that the authorities of the country in which the meeting is to take place guarantee free entrance of bona fide scientists from all countries.

Each Commission Chair is required to provide a written triennial report to the General Assembly. These reports are included as Appendices to the Agenda. Financial assistance has again been offered to the Commission Chairs, to enable them to attend the General Assembly for the presentation and discussion of their reports and to meet the Executive Committee prior to the General Assembly.

The reports of the Representatives on these bodies are given as separate Appendices to the Agenda.

There have been some staff changes during the triennium. The present members of staff in the IUCr offices in Chester are: Mr M.H. Dacombe (Executive Secretary), Mrs A. Cawley (Part-time Administrative Assistant to the Executive Secretary), Mrs M.J. Robinson (Part-time Secretary to the Executive Secretary), Mr P.R. Strickland (Managing Editor), Mrs S.E. King (Technical Editor), Mr B. McMahon (Research and Development Officer), Dr A.S. Berry (Assistant Technical Editor), Miss C.A. Moore (Editorial Systems Developer), Dr G.F. Holmes, Mrs L.E. Clark-Jones, Mrs J.K. Bradshaw, Mr S. Conway and Dr N.J. Ashcroft (Senior Editorial Assistants), Dr A. Weight, Dr S. Froggatt, Dr S. Glynn and Miss F. Reid (Editorial Assistants), Dr M.A. Hoyland, Mr D. Holden and Dr D. Hoare (Research and Development Assistants), Mrs L. Rathbone and Mrs C. Cook (Secretaries) and Miss A.J. Sharpe (Promotions Officer).

On behalf of the IUCr, the Executive Committee wishes to express its deep gratitude to the British Crystallographic Association, on behalf of the Royal Society, for the invitation to hold the Eighteenth General Assembly and International Congress of Crystallography in Glasgow. It particularly wishes to thank the Chair of the Programme Committee, Professor J.A.K. Howard, and the Chair of the Organising Committee, Professor C. Gilmore.

The continuing support shown by UNESCO in the form of its annual subvention received by the IUCr through ICSU, and the support of ICSU itself, is gratefully acknowledged.

Finally, the Executive Committee wishes to thank all crystallographers who have assisted in the work of the IUCr in so many ways. This cooperation between crystallographers of different nationalities constitutes a most valuable aspect of the IUCr's activities.

The accounts of the IUCr for the calendar years 1996 and 1997 have already been published [Acta Cryst. (1997). A53, 814—852 and (1999). A55, 585—600]. The accounts for 1998 have been audited and will be published in due course in Acta Crystallographica Section A. The accounts for the three years 1996, 1997 and 1998 are summarised in Tables 1—15. All amounts are expressed in Swiss Francs. The notations used in this report for the various currencies of the IUCr's activities are CHF = Swiss Franc, GBP = Pound Sterling, USD = US Dollar, NLG = Netherlands Guilder, DKK = Danish Kroner.

Table 1 shows a comparison of the fund accounts at the beginning and the end of the triennium. The total assets have increased by CHF 1,691,377 from CHF 5,224,690 to CHF 6,916,067, or 32%, over the triennium. It should be noted that these figures include the fluctuations in exchange rates. If the exchange-rate fluctuations are disregarded, the total assets increased by CHF 1,266,115 from CHF 5,968,695 to CHF 7,234,810, or 21%, over the triennium.

Table 2 shows the distribution of the assets. The debtors includes, in part, the IUCr's funding of the Glasgow General Assembly and Congress paid in advance. The great majority of the other amounts under debtors and creditors have since been settled.

The total investments at 31 December 1998 are CHF 6,163,824 at market value, as shown in Table 2, of which 23% is held by Merrill Lynch, 60% by Foreign & Colonial and 17% is held in UK Treasury Gilts. The IUCr bank accounts and short-term deposits are held with the Union Bank of Switzerland, the National Westminster Bank and Merrill Lynch, involving the currencies CHF, GBP, and USD.

As an association incorporated in Switzerland, the IUCr is exempt from Swiss Federal and Geneva Cantonal Tax. Under the terms of the United Kingdom/Switzerland Double Taxation Agreement dated 8 December 1977, investment income arising within the UK under present circumstances is not subject to United Kingdom tax. Investment income received from other countries with which Switzerland has a Double Taxation Agreement is also exempt from tax. In October 1985 a recognition of tax exempt status in the USA was received from the Internal Revenue Service, Department of the US Treasury.

Table 3 shows the accounts for the General Fund (GF) and Table 4 compares these accounts for the triennium with the budget approved by the Seattle General Assembly. This fund carries the income and expenditure related to the IUCr's administration and its regular scientific activities other than publications. The income has two main sources, the subscriptions from Adhering Bodies and the interest income from investments and bank accounts. The subscriptions from Adhering Bodies are based on the unit contribution, which was CHF 1,000 for 1996, 1997 and 1998. The total number of membership units was 152 for each year, while the budget was based on 151 for each year. The yield from investments is less than the budgeted amount by CHF 223,035.

The administration expenses for the journals are calculated as 35% of the general administration costs of the IUCr, including the work of the Executive Secretary and his office and of the General Secretary and Treasurer. The Executive Committee met annually, while the Finance Committee held two meetings in each of 1996, 1997 and 1998. The cost of these meetings varies, as seen from Table 3, depending on the location and the circumstances. In Table 4 they are included in the expenses of administrative meetings, together with the costs of the IUCr representatives on other bodies. The expenses of scientific meetings in Table 4 include the travel grants and other expenses for the Seattle Congress in 1996, the cost of the 1998 meeting of the Programme Committee for the Glasgow Congress, the expenses of the non-publishing Commissions, financial support to meetings and schools, the expenses of the three IUCr50 symposia held in association with the meetings of the Regional Associates in 1998, and expenses incurred in connection with STAR/CIF and the IUCr/FIZ Agreement. The financial support for young scientists attending meetings and schools is charged to the Research and Education Fund, see Table 13. In Table 4, the unfavourable deviation from budget of CHF 334,417 is largely accounted for by a lower than predicted return on investments and an increase in administration costs, most of which are incurred in GBP. The increase in administration costs is attributable to the strong increase (25%) in the value of the GBP against the CHF that occurred during the triennium.

Table 5 gives the account for the President's Fund. It is intended mainly for use in emergencies and under special or difficult circumstances, to help crystallographers from countries with currency problems to take part in the activities of the IUCr.

Tables 6, 7 and 8 give the accounts for Acta Crystallographica (AC), the Journal of Applied Crystallography (JAC) and the Journal of Synchrotron Radiation (JSR). In view of the significant costs involved in publishing Special Issues, the difference between the actual costs incurred and the contribution received from the conference organisers is charged to the Publications and Journals Development Fund. The total number of pages printed for AC, JAC and JSR were 7,681, 6,329 and 7,937 in 1996, 1997 and 1998, respectively. The Finance Committee (FC) and the Executive Committee (EC) have monitored the financial development for all journals very closely. Taking account of the different costs involved in producing each journal (those with a significant colour content are more expensive to produce), the prices were increased differentially during the triennium, with Section D of AC, JAC and JSR receiving the higher increases. The total number of subscriptions (including full and reduced-rate) decreased by about 6% for AC and 10% for JAC over the triennium. JSR was launched in 1995, with an inaugural issue in October 1994; it was distributed free of charge in 1995. The numbers of subscribers were 253, 269 and 288 in 1996, 1997 and 1998. The proportion of reduced-rate subscribers to JSR is high (48%) compared to the other journals (typically 15%). For further details see the Triennial Report by the Chairs of the Commission on Journals (Appendix 10 to the Agenda).

The Structure Reports accounts are shown in Table 9. This Fund was closed in 1996, when the final volumes were published, and the balance transferred to the Publications and Journals Development Fund.

The International Tables accounts are shown in Table 10. The costs of printing and reprinting the various volumes are charged to the appropriate years. Sales of Volume C were low in 1998 when it became out of print (pending the publication of the Second, Revised Edition in 1999). For further details see the Triennial Report by the Chair of the Commission on International Tables (Appendix 11 to the Agenda).

Table 11 gives the accounts of the Book Fund. The accumulated balance of this fund increased during the triennium. The main activity concerned the publication and sale of the Tenth Edition of the World Directory of Crystallographers.

Table 12 shows the accounts of the Publications and Journals Development Fund (PJDF). This fund was established in 1984 and has been built up through transfers from other funds, such as AC. In order to build up the fund further and in a systematic way, with the goal to make it self-supporting, the EC decided to increase its balance by crediting it with interest currently calculated as 6% of the balance of the fund, as shown in Table 12. During the triennium the major expenses are related to the purchase of computer hardware and software, programming and development, an electronic publishing project aimed at producing all the journals in SGML format in preparation for on-line publishing, the appointment of a Promotions Representative and Special Issue costs (see Journals Funds above). As the programming and development costs underpin much of the Union's activity, in 1997 the EC decided that these cost should be assigned to the Journals Funds, the International Tables Fund and the General Fund, in proportions based on the annual expenditure in these Funds.

It is the EC's policy to support and encourage the IUCr's highly qualified staff by supplying them with the best equipment.

Table 13 shows the accounts of the Research and Education Fund (REF). The fund was also established in 1984 and, like the PJDF, has been built up through transfers from other funds. As for the PJDF, this fund is currently increased by 6% per year, taken from the interest income, with the goal to make it self-supporting. CHF 232,624 was given as young scientists' support during the triennium.

The accounts of the Ewald Fund are given in Table 14. The interest on the capital is intended to cover the costs of the Prize. It is calculated as 6% of the balance in the fund, and is taken from the total annual interest income received from the IUCr's investments, in the same way as for the interest credited to the PJDF and the REF. The balance of the interest from the investments is credited to the GF. An additional CHF 100,615 has been transferred to the fund during the triennium.

Table 15 shows the accounts of the Newsletter Fund (NF). The fund was established in 1994 following the successful launch of the IUCr Newsletter in 1993 (when the expenses were charged to the GF). The IUCr Newsletter is currently distributed free of charge to 587 libraries and 15,000 crystallographers and other interested individuals in 39 countries. The costs to the IUCr were CHF 66,950 in 1996, CHF 84,574 in 1997 and CHF 74,059 in 1998.

The establishment of the Ewald Prize, for outstanding contributions to the science of crystallography, was announced in February 1986 and was given wide publicity. The name of the Prize was chosen with the kind consent of the late Paul Peter Ewald, to recognise Professor Ewald's significant contributions to the foundations of crystallography and to the founding of the International Union of Crystallography, especially his services as the President of the Provisional International Crystallographic Committee from 1946 to 1948, as the first Editor of the IUCr's publication Acta Crystallographica from 1948 to 1959, and as the President of the IUCr from 1960 to 1963.

Shortly after the death of Professor Ewald, his family informed the President that Professor Ewald had wished to make a bequest to the IUCr. After consulting Mrs Ewald, this generous bequest, together with a donation from the Ewald family and a donation from the IUCr, was used as starting capital for the Ewald Prize. The interest from this capital and further donations from the IUCr are used to finance the Prize.

The Prize consists of a medal, a certificate and an award of US $30,000. It is presented once every three years during the triennial International Congresses of Crystallography. The first Prize was presented during the Perth Congress, being awarded jointly to Professor J.M. Cowley and Dr A.F. Moodie. The second Prize was presented during the Bordeaux Congress to Professor B.K. Vainshtein. The third Prize was presented during the Beijing Congress to Professor N. Kato. The fourth Prize was presented during the Seattle Congress to Professor M.G. Rossmann.

In May 1999 it was announced that the fifth Ewald Prize had been awarded to

for his outstanding contributions to the field of crystallography: in the area of anomalous scattering and its use in the solution of the phase problem, in the analysis of the structure of fibres, collagen in particular, and, foremost, for his fundamental works on the macromolecular conformation and the validation of macromolecular structures by means of the 'Ramachandran plot', which even today remains the most useful validation tool.

The presentation of the Ewald Prize will be made during the Congress Opening Ceremony.

In the last triennium a number of developments for the IUCr journals should be highlighted. In the triennium the 50th Anniversary of Acta Crystallographica and the IUCr occurred, as did the 30th Anniversary of the Journal of Applied Crystallography. A special 50th Anniversary Issue of Acta Crystallographica was published in Section A in November 1998, comprising especially commissioned articles. The Guest Editor was H. Schenk whose excellent work and contribution is acknowledged here. This special issue was distributed to all subscribers of IUCr journals free of charge and is available for purchase at a very competitive price in book form. Authors' choice within the IUCr journals is broad, encompassing all aspects of crystallography and its cognate subjects across the sciences. The further expansion into the synchrotron field has been greatly facilitated by the Journal of Synchrotron Radiation, which has published the major proceedings from SRI '97 held in Himeji, Japan, and also the XAFS X Conference held in Chicago, USA, in 1998. The biological community expands apace and Acta Cryst. Section D (Biological Crystallography) is now published monthly. Publication of the very popular Daresbury CCP4 Conference Proceedings series commenced as a supplement to Acta Cryst. Section D in 1998. Chemical crystallography capability has also greatly expanded and to handle this all crystal structure data for publication in Acta Cryst. Sections B and C are now submitted electronically in the Crystallographic Information File (CIF) format. The Journal of Applied Crystallography has continued as a very successful publication and a new section on cryo-techniques is proving popular.

The IUCr web coverage of the journals, including the services to authors and Co-editors for manuscript tracking, is extensive. A 50-year searchable index has been introduced and this is a powerful tool for accessing the vast archive of IUCr publications. Most recently, proofs have been made available electronically to authors. Preparation for web access to the journals themselves is most advanced for Acta Cryst. Section D and release is imminent at the time of writing. The upcoming triennium includes an expansion of this electronic access for subscribers to the IUCr's journals.

There is a greater emphasis on the marketing of the journals to the crystallographic community, as well as to structural science communities in biology, chemistry, materials science and physics. Highlighting via mini-reviews of IUCr journal articles within the IUCr Newsletter has commenced. This opens a channel to 15,000 readers and is clearly an exciting promotional strategy. Details of each journal can be found in the accompanying reports below.

At the end of this triennium we say farewell to Section C Editor S.R. Hall who has steered Section C firmly and effectively into the electronic era, spearheading developments adopted now by various other structural chemistry and physics based journals. Also, A.M. Glazer has kept the Journal of Applied Crystallography at the forefront of experimental techniques, and launched various new sections in the journal. They are warmly wished an enjoyable and well earned respite from their heavy workloads.

In the triennium 1996—1998, Section A has published 18 bimonthly issues and a Special Issue dedicated to the 50th Anniversary of Acta Crystallographica and the IUCr. The total number of pages was 2,922, corresponding to 227 Research Papers, 3 Lead Articles, 2 Topical Reviews, 26 papers in the Special Issue, and 32 Short Communications. The number of pages and of papers published in 1997 was low, but picked up again in 1998. Many efforts have been devoted successfully at every stage to reduce the processing and printing times. The average review time is down to about four months. Efforts will continue to be made to address this crucial issue.

A highlight of the year 1998 was the Special Issue celebrating the 50th Anniversary of Acta Crystallographica and the IUCr. Its Guest Editor was H. Schenk. The Special Issue starts with a paper about the history of the IUCr and spans all aspects of crystallography, symmetrical, structural, physical, chemical and biological, with papers devoted to the most important landmarks in the development of crystallography over the past 50 years. It has also been printed as a book, under the title Crystallography Across the Sciences. This Special Issue is undoubtedly a success and more are planned. More Lead Articles and Topical Reviews are also in the pipeline.

The format of Section A seems well adapted to its purpose and no suggestions to modify it have been received in the past, but any suggestion for modification and improvement will be welcome.

In the triennium 1996—98, Section B has published 3,066 pages, comprising 335 full Research Papers, 16 Short Communications and 3 Topical Reviews (with more in the pipeline). The chemical balance of these papers is ca 45% dealing with inorganic materials, 15% dealing with metal-organics and 40% dealing with organics. Apart from papers reporting structural studies from this broad chemical spectrum, Section B continues to serve the needs of those working on charge density studies, structural systematics from the inorganic and small-molecule databases, the modelling and prediction of crystal structures, powder diffraction methodologies, studies of phase transitions, etc. The quantity of review material carried by Section B has been lower than expected. However, the value of this material lies in its quality, and it is no easy matter to secure authoritative material of this kind. Following a slight downturn in papers at the beginning of the previous triennium, coincident with the launch of Section D and the loss of biologically oriented papers, Section B has now recovered its normal average output of 1,000+ pages per annum.

Technically, Section B has come a long way during the period. CIF submission has become mandatory for structural papers, many other papers are received in machine-readable form, and in-house typesetting at the Chester office has been introduced. This latter project caused the first two issues of 1998 to be smaller than usual (ca 10 papers each), but later issues in that year soon returned to the norm of more than 20 papers per issue.

In 1997, procedures were set in place to reduce publication times. A major component of the longer publication times has been the time taken by authors to revise manuscripts in light of referee comments. This time has now been reduced to a maximum of three months, with most authors revising in much shorter times than this. Now that the in-house typesetting is in place, we would expect to see shorter publication times from 1999 onwards.

Impact statistics show that Section B remains fourth of seventeen current crystallography journals, just behind three other IUCr publications. A 'citation half-life' of more than 10 years reflects the lasting value of Section B papers.

A number of important changes have been made to the editorial and publication procedures of Section C during this triennium. Most have flowed from decisions made at the Commission meetings at the Seattle Congress in response to a rapid expansion in journal page numbers and significantly increased publication costs. The decisions spawned a number of initiatives which are intended to make the publication of structural studies more efficient for authors and the journal.

In 1997 a new electronic publication mode, known as CIF-access, was introduced. This provides for the fast, minimum-text, publication of structure determinations. The CIF-access paper is not printed but its title, scheme and synopsis appear in the Contents page of the journal in the month that the submitted material is deposited in the IUCr CIF archive. A CIF-access submission is checked identically to a full paper except that the text entries remain the responsibility of the authors. In 1998 seventy six CIF-access papers were published.

In Seattle the Section C board decided that specific quality standards were needed to promote consistent acceptance criteria for structural data, and to provide explicit author guidelines on the submission requirements. These criteria were introduced into the 1997 Notes for Authors, and became the basis for CIF checking within the Chester office. They have remained essentially unchanged over the triennium and are largely responsible for the higher quality of papers currently being published by the journal.

Another change instituted in 1997 was the removal of the atomic coordinate/anisotropic displacement parameter tables from the printed paper, except in special cases. This reduction in printed structural data was possible because archived CIFs can now easily be accessed via the IUCr web site, and this approach is more efficient and reliable as a source of structural parameters than the printed page. The recent availability of software which can be linked to the web browser means that published structures may be easily down-loaded, examined and manipulated, with a few mouse clicks. These and other web services are, as planned, providing new approaches to examining published structures, and are certain to influence the future publication directions of Section C.

The most recent change to Section C operations has been the introduction of a comprehensive suite of automatic validation and checking tests. These are used in the Chester office and as part of the, now mandatory, CHECKCIF facility. These tests are accessible via e-mail or the web. The algorithms used in this checking suite are based primarily on the criteria defined in the 1997 Notes for Authors, with the addition of 'alert level' messages to indicate the degree of departure from the expected standard. The requirement that authors pre-check their CIFs prior to submission using CHECKCIF has meant that less time and effort is wasted by authors and editorial staff on faulty submissions. In addition, authors now receive much more detailed information about the review expectations of the journal. If the author believes that any of the reported error alerts are inappropriate for a particular study, this can be explained in a supplied electronic form, known as the Validation Response Form (VRF). The VRF is, if need be, inserted into the CIF submitted for publication, and the explanations are assessed and handled by a special Co-editor prior to the normal review step. The automatic checks have effectively shifted the emphasis of data validation and checking from the editorial office to the author, and this is of long term importance to the efficiency of the journal, and to knowledge within the discipline.

The changes to Section C in this triennium represent the transition to faster, more efficient publication modes for delivering structural information, and ensure a consistently high standard of publication through explicit acceptance criteria. The magnitude and speed of these changes has certainly stimulated some authors and, not unexpectedly, been more difficult for others. As expected of an IUCr journal, these efforts are pioneering future approaches to structural publications. This has involved a considerable effort on the part of the Chester office staff and the members of the Section C board. Their large contributions are most gratefully acknowledged.

Section D, devoted to biological crystallography, started in 1993 as a publication that appeared every other month. Since January 1999 it has appeared monthly. It contains Fast Communications, Topical Reviews, Research Papers, Short Communications, Crystallization Papers, Book Reviews and Letters. In addition, the Proceedings of the CCP4 Study Weekend, January 1998, entitled 'Databases for Macromolecular Crystallographers' was published as Part 1 of the November 1998 issue. Articles on results of crystallization experiments continue to provide important and useful information on macromolecules under study. In order to be published in Section D, deposition of all crystallographic data on biological structures (atomic coordinates and structure factors) at the Protein Databank is required. This deposition is generally as mmCIF files, so that data are available for re-refinement if needed. Publication of figures in colour is provided free of charge, but only when the colour adds to the scientific content of the article. In addition, all authors are asked to sign a form attesting to the fact that they have seen the final manuscript; this is done to obviate some problems that have occurred in the past. I thank J.R. Helliwell, the Editor-in Chief, and P.R. Strickland, the Managing Editor, for their continued support and advice through the last few years.

The subjects of research papers have included structures of a wide variety of proteins and nucleic acids. Of these, many interesting structures reported were those of a channel-forming integral membrane protein and an enzyme containing a transition-state structure in the active site. New structures, refinements of structures already known, structures of enzymes from different biological sources with somewhat different modes of action, structures as large as those of viruses, nucleosomes and ribosomes, were all reported in this journal. Details of intermolecular associations, including hydrogen bonding between water and aromatic groups, were also analysed.

The methods used to obtain such interesting structures were reported, with several articles that addressed the experimental problems encountered, how to overcome them, and discussion of the credence that should be given to the three-dimensional information that results. Subjects of articles included techniques for cryogenic data collection, methods of analysis of diffraction patterns, synchrotron data collection, X-ray structure analyses combined with electron microscopy, and the use of krypton and xenon as heavy atoms in proteins. Problems with twinning and the assignment of space group were also discussed. Crystal structures of macromolecules and their complexes are now being reported at 1.2 to 1.4 Å resolution, so that anisotropic displacement parameters and ordering of side chains at low temperatures can be evaluated. Those articles involving crystallization research addressed heterogeneity effects, descriptions of imperfections in protein crystals, comparisons of crystal growth in magnetic fields and in space and on earth, and the use of isothermal microcalorimetry, dynamic light scattering, NMR and Raman spectroscopy to study nucleation, orientational disorder, the mode of breakdown of protein crystals on melting and the structural effects of flash freezing of a crystal. Macromolecular crystal growth kinetics and morphology and the formation of polymorphs were also analysed. Articles describing methods of phasing the diffraction data involved multiple wavelength anomalous scattering with a variety of scatterers in the crystal, the various methods of density modification, phase improvement, and error estimates in macromolecular structure determinations. Molecular replacement was the subject of many articles, and it was shown that similar proteins need not necessarily associate in the same way. Patterson and real-space methods of structure determination were also addressed. Triplet phases from three-beam diffraction have been used to initiate direct methods for high-resolution protein data. Refinements of many macromolecular structures provided a more detailed picture of the atomic arrangement and the molecular folding, and several articles addressed ways of determining the reliability of a protein structure determination. Pitfalls and cautionary tales on these methods will be helpful to others with problems solving their structures.

The focus on crystallographic databases that was provided by the CCP4 Proceedings comes at a time when there is particular interest in this subject as a result of the general use of the web. Those databases of protein and nucleic acid structures, currently in place, were described together with other available databases, including those of structural motifs, intermolecular contacts and protein sequence alignment techniques. The organisers, J. Murray-Rust, L. Potterton, B. Luisi, E. Dodson and S. Bailey, are to be thanked for a highly useful publication. Previous proceedings of CCP4 study weekends have been published as Daresbury Laboratory technical reports, but it was felt that Section D would reach a wider audience.

Our sincere thanks to the many members of the crystallographic community who have served as reviewers of submitted papers. The staff at Chester have done an excellent job in shepherding the articles to the publishers, and they are also thanked. The Co-editors are also deserving of our thanks; they oversee the publication fate of a large proportion of the submitted manuscripts. Without their careful work the expansion of the journal to a monthly issue in 1999 would not have been possible.

An analysis of the contents of the Journal of Applied Crystallography over the last triennium is presented below:

Note that in 1997, the first numbers under Pages and Research Papers refer to the Special Issue containing papers presented at the Small-Angle Scattering Conference held in Campinas, Brazil. Publication of this Special Issue resulted in a slowing down of the normal publication cycle, but this matter has now been addressed, so that new arrangements for the publication of Special Issues should not interfere seriously with the normal journal production.

Even excluding the Small-Angle Scattering issue, certain healthy trends are apparent. In particular, there has been a steady growth in the number of pages published, most obviously seen in the increase in normal Research Papers. This is clearly a good situation for a journal in the present climate where electronic publication may be seen as a possible threat to paper publishing. It is gratifying also to see that the new Cryocrystallography section has shown signs of becoming popular, especially in the most recent year. Similarly the new Teaching and Education section is looking like it will be a valuable part of the journal in the future. It is also apparent that the Journal of Applied Crystallography remains the most significant of the IUCr journals carrying details about crystallographic software, although it has to be said that the Software Reviews section has been disappointing, and will need further consideration.

It is now more than four years since the Journal of Synchrotron Radiation (JSR) was launched. In this time approximately 500 research articles in over 2,400 pages have been published, providing a focus for the whole of the synchrotron radiation community. The number of papers published in JSR over the triennium has steadily increased. For the journal, the main achievement of the triennium was the successful publication of the SRI '97 Proceedings, the largest ever undertaken by the IUCr journals team, comprising over 1,050 pages. The papers for that issue were refereed to the usual JSR standards, rather than at the meeting, and we believe that this effort is reflected in the improved quality of the Proceedings over those published previously. The SRI '97 Proceedings formed the May 1998 issue of JSR. Many of the lessons learnt with SRI '97 were applied to the Proceedings of the XAFS X Meeting, held in Chicago, USA, August 1998, which is to be published in May 1999. This was again fully refereed but was produced in camera-ready format.

We have entered into the citation ranking tables and are already ranked third out of thirty seven journals covering instruments and instrumentation with Review of Scientific Instruments placed fifth, NIMS B placed sixth and NIMS A placed eighth. The review and production times for the journal have been rapid. Centralised submission was introduced in 1997 and is being used to improve review times; our current strategy is to cut production times by increasing electronification of the journal. We are currently putting together a Synchrotron Radiation and Structural Biology Special Issue (July 1999 issue of JSR) to celebrate J. Walker's (now Sir John Walker) share in the 1997 Nobel Prize in Chemistry, which is indeed the first synchrotron-radiation-related Nobel prize. Overall, the high impact factor for the journal and its excellent review and publication turn-around times for authors are fine achievements, indeed making us the best journal for the synchrotron radiation community's papers in synchrotron radiation instrumentation, methods and applications.

During the Seattle Congress the Commission held one Open Meeting and three closed meetings, in addition to numerous personal contacts between volume editors, technical editors and authors. The Open Commission Meeting featured six lectures on the status of the International Tables volumes, either published or in preparation. Reports about this meeting are available on the web as part of the IUCr home page (see below), in the Newsletter of the British Crystallographic Association (No. 58, September 1996; No. 59, December 1996), and in the IUCr Newsletter (Vol. 5, No. 2, 1997). Another Open Commission Meeting will be held at the Glasgow Congress.

At their Seattle meeting the Executive Committee approved two new International Tables volumes:

Volume F: Macromolecular Crystallography, editors M.G. Rossmann and E.A. Arnold;

Volume G: Crystallographic Information, editors B. McMahon and S.R. Hall.

A summary of the information on all volumes of International Tables, either published, in the process of revision, or being prepared or planned, has been collected in the form of a home page of the Commission. It is accessible from the main IUCr home page (http://www.iucr.org/) and the sub-pages (i) Activities of the Commissions, and subsequently (ii) Commission on International Tables for Crystallography. The home page is maintained by U. Shmueli in Tel Aviv and its updated versions are retrieved by B. McMahon at the IUCr office in Chester.

During ECM-17 at Lisbon, Portugal, August 1997, all Commission members present met with the IUCr’s Managing Editor, P.R. Strickland, in order to discuss the future production and printing schedules of all International Tables volumes, in particular of those volumes ready for publication or for a new edition (Volumes A, B, C, E). Subsequent changes to this schedule were transmitted to all persons concerned.

In the spring of 1998 a new volume of International Tables was proposed by U. Müller, Kassel; the volume is tentatively called ‘A2’ and has the title: Relations of Wyckoff Positions between Space Groups and their Maximal Subgroups. The proposal is presently being considered by the Executive Committee.

Detailed reports on the individual volumes of International Tables are given below. Table 1 contains sales and stock figures for the volumes that are currently active.

Table 1. Sales and stocks of volumes published up to 31 December 1998

Volume A. Space-Group Symmetry; Editor Th. Hahn

The Fourth, Revised Edition of Volume A, published in March 1995, has sold so well that a Corrected Reprint became necessary, which appeared in October 1996. It contains corrections of all errors and flaws known at that time. A further reprint became necessary and appeared in June 1998.

The Fourth, Revised Edition of the Brief Teaching Edition of Volume A appeared in October 1996. It is based on the Corrected Reprint of the Fourth, Revised Edition of Volume A, mentioned above.

Preparations for the Fifth, Revised Edition of Volume A continued throughout the triennium. This edition will be completely ‘computerised’ in the following ways:

(i) The space-group tables in this volume (Sections 6 and 7) are being transferred to LaTeX files by M. Aroyo and his colleagues in Sofia, Bulgaria. These files will be the basis for the printing of the Fifth Edition. This work was completed by the end of 1998; checking of the data is in progress.

(ii) The remaining text sections will be re-keyed in Chester. The SGML conversion of these sections will be carried out in the second half of 1999.

The new edition will have a substantial number of corrections and small improvements. Three larger changes stand out:

(i) Systematic introduction of the new symbol ‘e’ for the ‘double glide plane’ throughout the volume; this symbol was first used in the Fourth Edition, but in a few places only.

(ii) Addition of a small new Section 9.4: Some Further Properties of Lattices by B. Gruber, Prague, Czech Republic.

(iii) Revision of some parts of Section 15 on normalisers, especially Table 15.3.2.

The scheduled publication date of the Fifth Edition is now the spring of 2000.

The Fifth Edition of Volume A will also be the basis of the Fifth Edition of the Brief Teaching Edition of

Volume A.

The First Edition of Volume B was published in 1993, a Corrected Reprint appeared in 1996 and the work on the Second Edition was at a fairly advanced stage during the Seattle Congress. The editorial work on the Second Edition was completed during the triennium 1996—1998. All the material received from the authors is in the hands of the Technical Editor in Chester.

As pointed out in previous annual reports, the publication of the Second Edition of Volume B (as well as other volumes of International Tables) was delayed by the recently undertaken translation of the Tables to Standard Generalised Mark-up Language (SGML) which will facilitate their access through a variety of electronic media.

We summarise here all the major revisions in the First Edition of Volume B, and the newly incorporated contributions to the Second.

Revised/corrected chapters and sections (for the Second Edition):

B.1.2. The structure factor (by P. Coppens)

B.1.3. Fourier transforms in crystallography (by G. Bricogne)

B.1.4. Symmetry in reciprocal space (by U. Shmueli; revised Appendix B by U. Shmueli, S.R. Hall and

R.W. Grosse-Kunstleve)

B.2.1. Statistical properties of the weighted reciprocal lattice (by U. Shmueli and A.J.C. Wilson)

B.2.3. Patterson and molecular-replacement techniques (by M.G. Rossmann and E. Arnold)

B.2.5. Electron diffraction and electron microscopy in structure determination — Foreword (by J.M. Cowley)

B.2.5.2. Space-group determination by convergent-beam electron diffraction (by P. Goodman)

B.3.3. Molecular modelling and graphics (by R. Diamond)

B.4.1. Thermal diffuse scattering of X-rays and neutrons (by B.T.M. Willis)

B.5.1. Dynamical theory of X-ray diffraction (by A. Authier)

New contributions (to the Second edition):

B.1.5. Crystallographic viewpoints in the classification of space group representations (by M.I. Aroyo and

H. Wondratschek)

B.2.5.6. Direct methods in electron crystallography (by D.L. Dorset)

B.4.5. Polymer crystallography (by D.L. Dorset and R.P. Millane)

B.4.6. Reciprocal-space images of aperiodic crystals (by W. Steurer and T. Haibach)

B.5.3. Dynamical theory of neutron diffraction (by M. Schlenker and J.-P. Guigay)

The scheduled publication date of the Second Edition of Volume B is January 2000.

At the time of the Seattle Congress the task of assembling material for a Second, Revised Edition of Volume C was largely complete. Although most of the text of the First Edition had been composed by the authors on one word-processing system or another, very few of the original computer files still existed in any machine-readable form, and, as a result, a large part had to be typeset manually for the Second Edition. The manual typesetting has been carried out with a computerised system used by commercial printers, and the entire contents now exist as machine-readable files. One by-product of this procedure was that numerous entries whose authors had initially said that they did not want to revise them actually were substantially revised at the galley proof stage. As of January 1999 the entire volume, except for some front and back matter, was in page proof, and the project was on schedule for publication in the spring of 1999.

The First Edition contained several chapters and sections that had been carried over from the earlier series of International Tables, and some of the data was from the 1930's. Only one of these chapters remains, and that was judged to be sufficiently authoritative not to require revision. The Second Edition contains two entirely new chapters, and many others have been substantially rewritten. The timely completion of the Second Edition could not have been achieved without the cooperation of the many authors and the staff in Chester, and the entire crystallographic community is in their debt.

The preparation of Volume D has progressed steadily during the triennium. The few manuscripts still missing are expected to be delivered during the first half of 1999. The manuscripts, which were already in the hands of the Editor, were updated by their authors during 1998, and the whole volume will be sent to the Technical Editor in July 1999, even if one or two manuscripts are still outstanding. Volume D will include two accompanying software packages on a CD ROM. The first, dealing with tensors and irreducible representations, calculates representations of finite three-dimensional point groups and the components of invariant tensors in arbitrary dimension, of arbitrary rank, and with arbitrary permutation symmetry of the indices under the action of a three-dimensional crystallographic point group. The second, dealing with phase transitions, will give tables for equitranslational phase transitions, and for tensor properties at any group—subgroup phase transition: spontaneous tensor components, up to rank four, that appear in the distorted phase and non-zero tensor components that are the same in both phases.

Two meetings took place, the first in Nijmegen, The Netherlands, in February 1997 and the second in Prague, Czech Republic, in January 1998, in order to define and coordinate the contents of the two software packages. Alpha versions have been produced and tested. A beta version of the CD ROM including the two packages and a presentation page prepared by the IUCr Research and Development Officer should be ready for distribution in the spring of 1999.

A final draft of Volume E was prepared with the following content:

Part 1: Subperiodic Group Tables: Frieze Groups, Rod Groups, and Layer Groups

Section 1: Symbols and Terms used in Part 1
Section 2: Guide to the Use of the Subperiodic Group Tables
Section 3: The 7 Frieze Groups
Section 4: The 75 Rod Groups
Section 5: The 80 Layer Groups

Part 2: Scanning of Space Groups

Section 6: Symbols and Terms used in Part 2
Section 7: Guide to the Use of the Scanning Tables
Section 8: The Scanning Tables.

The scheduled publication date of Volume E is April 2000.

Our goal in preparing Volume F of International Tables is to produce a comprehensive, yet concise, reference work for macromolecular crystallography. This first International Tables volume devoted to macromolecular crystallography is intended to complement the existing volumes as well as other reference materials pertinent to modern structural biology. The emergence of Volume F recognises the increasing size and vitality of the field of macromolecular crystallography. It is hoped that this volume will be particularly useful for at least 10 to 12 years.

Volume F will cover the theory and practice of macromolecular crystallography with an estimated total of 700 pages. In addition, there will be surveys of the principles of macromolecular structure and of commonly used macromolecular crystallographic program systems. Approximately 100 authors have accepted invitations to write 95 articles in a total of 27 chapters. Two advisors and an international Advisory Board consisting of 27 members have assisted in the planning of the volume. A web site at the IUCr Offices at Chester (address: http://www.iucr.org/~commit/itf/) has been set up to facilitate inter-author communication during the preparation of the volume. The volume will include numerous figures in colour and a CD ROM version will be produced to provide electronic access to the volume and accompanying materials.

As of January 1999, manuscripts have been received for approximately three-quarters of the projected articles in the volume. The papers are reviewed for scientific content and overall consistency of style and expression; completed manuscripts following revisions are sent to the IUCr offices in Chester. The overall quality of the contributions received is very high. We anticipate that most articles will have been completed by the time of the Glasgow Congress and hope that Volume F will be completed and published in 2000.

Volume G was approved by the Executive Committee at the Seattle Congress as a reference handbook for crystallographic information, and specifically in its early editions as a documentation of the Crystallographic Information File (CIF) project. Chapters in the volume will document the file structure and formal grammar of CIF, the techniques and software libraries available for creating, editing and reading CIFs, and, most substantially, the definitions of public data names maintained by the IUCr. Much of the time since the Seattle Congress has been taken up with approving and maintaining dictionaries of definitions appropriate to small-molecule single-crystal structure determination, to powder diffraction studies, and to the determination and description of biological macromolecular structures. Now that these procedural developments have taken place, manuscripts are being collected from participants in the CIF project with a view to publication of Volume G in the latter part of 2000.

The publication of Volume A1, for some time named ‘Volume H’, was approved by the Executive Committee in August 1995. It provides complete tables and diagrams of the maximal subgroups for each space and plane group; for the Contents see the Report for 1995 in Acta Cryst. (1996). A52, 962.

Meanwhile, the data for the subgroup tables are complete and have been checked in several runs by hand, by the mathematical program system GAP, and by ad hoc programs. The homogenisation of the data on isomorphic and on non-isomorphic subgroups that originate from different sources is in progress. Many transformations from unconventional to standard settings have been changed in order to make the tables more user-friendly for the comparison of symmetry-related crystal structures. There are still problems to be settled, in particular for those space groups which are presented twice in Volume A because of different settings. The user’s guide and the theoretical part are in preparation. In addition to the tables, the subgroup relations will be presented in the form of diagrams, separate for translationengleiche and klassengleiche subgroups. These diagrams have been completed.

Dissemination and Storage of Information

In the triennium, the Committee on Electronic Publishing, Dissemination and Storage of Information (CEP) constituted a small and very active technical working group. The Committee suffered a tragic loss with the death of Professor E.N. (Ted) Maslen on 2 February 1997. In his role as Chair of the Working Party on Crystallographic Information, then as Director of Archiving and Crystallographic Information and then as founding Chair of this Committee, Ted guided the IUCr's publication and archiving activity into the electronic era through a tangled maze of options and opinions. The CEP was reinforced on 21 December 1998 by the appointment of L.M.D. Cranswick as a member.

A publishing consultant's study of activities of the IUCr was received in January 1996. The consultant recommended the use of SGML favouring a DTD modelled on the Elsevier Art(icle) DTD and conforming to ISO 12083. This is now the manner in which documents are treated in the editorial offices.

During the Seattle Congress, a microsymposium devoted to the Internet was organised by two members of the CEP, and the Committee's then Chair E.N. Maslen gave a very clear exposition of the Science, Technology and Economics of Electronic Publishing in Crystallography, and Y. Epelboin spoke on Internet Resources for Crystallography. The microsymposium also contained a talk from G.D. Purvis, an outsider to crystallography, on The Role of the World-Wide Web in Computational and Pharmaceutical Chemistry, and finished with short presentations on two hot subjects on the Internet, Java and VRML, both likely to have impact on the area of electronic publishing. Further, a workshop on the Internet was run to give participants hands-on experience.

In the period 1996—1999, on-line services based on the Internet have followed such a rapid and widespread development that it was not considered necessary to organise similar events in association with the Glasgow Congress.

Within the triennium, the CEP has expended considerable effort on the implementation and deployment of the IUCr web information service. This has been nurtured into a system with a unified design with content arising from distributed sources of information. A high priority is set on providing up-to-date information of use to the whole crystallographic community. During its meeting in Lisbon, Portugal, in August 1997 the IUCr Executive Committee delegated editorial powers for IUCr web services to the CEP. The information service needs its content to be increased by input from collaborating providers from the crystallographic community.

Within the triennium, deployment of mirror servers for the IUCr information services has passed from the stage of the non-existent to that of a fully functional, highly optimised set of mirror sites. The development involved not only overcoming the technical difficulties and improving the efficiency of file transfer but also of producing the policy documents detailing the responsibilities of site managers and National Committees. This policy was approved by the IUCr Executive Committee at its meeting in Lisbon in August 1997. The latest improvements involved a considerable restructuring of the file system at the Chester site. As part of this strategy for mirror sites, the IUCr has acquired the Internet second-level domain name iucr.org, permitting a unified naming of Chester and the mirror sites. The deployment of the mirror-site system depends on the good will and involvement of the IUCr members (i.e. the National Committees for Crystallography) in providing equipment with network connectivity to act as mirror sites for their country or region. Some regions of the world are inadequately covered at the moment, depriving crystallographers of a very important resource.

The CEP identified a need within the community for discussion forums operated by means of an e-mail list server. In early 1998 this became operational and the CEP drafted a Policy Document on Creation and Management of Discussion Lists, which received the approval of the IUCr Executive Committee. The IUCr list server provides facilities for e-mail-based discussion lists on topics relevant to the IUCr and the field of crystallography. At present the server is only lightly used.

A major revision of the World Directory of Crystallographers (WDC) was started at the beginning of 1996 and the National Editors were invited to prepare their data to be ready before the end of 1996. Subsequently, the tenth edition of the WDC was published and made available in printed form through a limited print run. The WDC was also made available for on-line consultation using a web interface on an industry-standard public-domain directory service. It has become apparent on many occasions that the procedures for updating the WDC were obsolescent. Consequently, a functional specification for a new implementation of the WDC as a relational database using technology parallel to, but not directly integrated into, the IUCr editorial-office production database is currently at the discussion stage. The design of this database is centred around the need to allow rapid, but supervised, updating of records in a secure manner. It is intended that it should be possible to consult the database on-line by a variety of the most popular industry-standard protocols.

The conversion of the Chester editorial office to electronic publishing using full-text SGML mark-up is virtually complete (apart from Acta Crystallographica Section C, which uses an entirely different production stream). The in-house production relational database is fully operational. The electronic on-line distribution of the IUCr's six journals will require an infrastructure that the Chester office is not in a position to provide itself, indeed in the same way that the printing, mailing and subscription administration for the printed journals is sub-contracted. The negotiations with the publisher (Munksgaard) for the electronic distribution of the IUCr's journals are continuing.

The CD ROM is an attractive medium for electronic publication. The CEP is supportive of L.M.D. Cranswick's NeXus project. In this, CD ROMs are produced just-in-time upon request in small quantities on a low-cost burner and are distributed to crystallographers in developing countries lacking a reliable Internet connection. The content contains a 'virtual' WWW of crystallographic information drawn from the IUCr information services and elsewhere, and a selection of public domain software of general use and for crystallographic applications. Over 40 CD ROMs have been distributed in this way. The CEP is collaborating in the project to produce the CD ROM for the Glasgow Congress. The CD ROM will contain the Congress Abstracts, material from the sponsoring organisation, a selection of the IUCr information services and a digitised copy of an out-of-print book. The CD ROM will be distributed to participants and will also replace the three-yearly printed supplement to Acta Crystallographica Section A containing the Congress Abstracts. The project will afford valuable experience in the production of CD ROMs and in the scanning and digitisation of books by a commercial service. The latter will be useful for the digitisation of all back numbers of the IUCr journals.

Contacts are being pursued with some other learned societies and publishers concerning the checking of their crystal structure data. It is projected that the web interface and criteria used for the checking of these data for Acta Crystallographica Section C could be adapted to the needs and requirements of the other interested parties as individual joint developments with participation in costs.

Three members of the CEP (Y. Epelboin, H.D. Flack and B. McMahon) accompanied by S.R. Hall and A. Authier attended the ICSU Press/UNESCO conference on Electronic Publishing in Science held in February 1996 in Paris. The conference brought together interested parties from learned societies, publishing houses and libraries in a series of formal presentations and working groups in which the technical, economic and social effects of electronic publishing in science were discussed. The CEP met during the Seattle Congress. H.D. Flack visited the IUCr Editorial offices, Chester, UK, in November 1996, November 1997 and November 1998.

Purpose

The purpose of COMCIFS is to commission and approve new CIF dictionaries and to keep the crystallographic community informed of its decisions. COMCIFS is a Sub-committee of the Executive Committee.

The members of COMCIFS during the triennium were: I.D. Brown (Chair), P.R. Edgington, P.M.D. Fitzgerald, S.R. Hall, G. Madariaga, B. McMahon (Secretary), M.A. Spackman, B.H. Toby. In addition, COMCIFS has had a number of consultants and observers who have received COMCIFS mailings and made important contributions to the discussions.

During the triennium, three dictionaries were approved, one was a revision and two were new. These were:

The second version of the core dictionary (core_cif.dic 2.0), which is used, inter alia, for submission of papers to Acta Cryst. Section C.

The dictionary for macromolecular structures (mm_cif.dic 1.0), which is being adopted by the Protein Databank and the Nucleic Acid Databank.

The dictionary for powder diffraction (pd_cif.dic 1.0), which is being adopted for the Powder Diffraction File.

Support for these dictionaries is provided by Dictionary Maintenance Groups chaired by I.D. Brown (core_cif.dic), P.M.D. Fitzgerald (mm_cif.dic) and B.H. Toby (pd_cif.dic). These groups are charged with consulting with their respective communities and preparing revised versions of the dictionaries as required.

Revisions proposed by the Dictionary Maintenance Groups are presented to COMCIFS for final approval. Revised versions of the core (2.1) and macromolecular (1.1) dictionaries are at an advanced stage.

Six new dictionaries are in various stages of preparation. These are:

A modulated structure dictionary (ms_cif.dic) which will be shortly presented to COMCIFS for tentative approval. It is being prepared by a group under the direction of G. Madariaga.

A dictionary for images (img_cif.dic) which is also nearly ready for presentation to COMCIFS for tentative approval. This is designed for storing diffraction patterns from two-dimensional detectors, but it will be able to store any two-dimensional image with extension to higher dimensions. Because of the size of the files and the need to process them in real time, a binary version of this CIF is also being defined. The ASCII and binary standards are identical except for differences needed to write and read a binary file. A. Hammersley is in charge of this project.

A small-angle scattering dictionary (sas_cif.dic), which is being constructed by a group headed by M. Malfois. A draft has been prepared.

A dictionary for magnetic structures (mag_cif.dic), which is being prepared in conjunction with the Database of Magnetic Structures Determined by Neutron Diffraction, headed by W. Sikora.

A dictionary for crystallographic symmetry (sym_cif.dic), which is under construction by a group headed by I.D. Brown.

A dictionary for electron density CIFs (rho_cif.dic), which, after a slow start, is being prepared by a group under P. Mallinson.

All COMCIFS formal business is conducted via an electronic discussion group whose transactions can be viewed by the public at http://www.iucr.org/iucr-top/lists/comcifs-l. In addition, regular reports on COMCIFS activity have appeared in the IUCr Newsletter.

A group is exploring questions of intellectual property rights related to CIFs and CIF-based software.

We are also working on a scheme to allow the automatic concatenation of different dictionaries at run time in order to allow one dictionary to incorporate other dictionaries that may be necessary for its proper functioning. This raises the question of whether we should continue to carry the overhead of maintaining CIF dictionaries in two incompatible Dictionary Definition Languages (DDL) or whether we should standardise on one DDL.

Proposals are being prepared which may allow dictionaries to express functional relationships between the different archived items.

It is my pleasure to thank the members of the committee, and others too numerous to mention, whose careful and often time-consuming efforts have made an essential contribution to the success of CIF.

The IUCr Newsletter is a vehicle to broadcast and promote the interests and activities of the IUCr and its

Commissions and Committees and to strengthen communication in the world community of crystallographers.

An effort is made to promote meetings and publications sponsored by the IUCr. Highlights of the eleven issues published during the triennium included extensive coverage of the Seattle Congress, preliminary information concerning the Glasgow Congress, a cover story on the IUCr web site, and articles covering the development of CIF formats.

The aim is to cover all areas of crystallography, both in the text and with the choice of cover illustrations. Cover illustrations in the triennium included small-molecule crystallography, macromolecular structures, fibre diffraction, small-angle scattering, the IUCr web site, and the Glasgow Congress site. Several covers were composites combining small-molecule, materials and macromolecular applications to emphasise the broad range and remarkable power of crystallography.

Eleven issues of the IUCr Newsletter were published from 1996 through 1998. The issues ranged in length from 16 to 32 pages. Each contained a letter from the President, news of IUCr Commission activities, crystallographic meeting announcements and reports, obituaries of prominent crystallographers, notices of elections, awards to crystallographers, and information on books, web sites, resources, and activities of interest to crystallographers. When available, information on meetings and advances in electron diffraction, neutron diffraction, amorphous materials, and quasicrystals, and other related topics are published. Contributions from crystallographers everywhere are sought; material is gathered from newsletters of crystallographic associations and societies and from leading science news magazines. Photographs are provided by contributors or drawn from the personal collection of the Editor. Almost all contributions are published and all material is edited to varying degrees.

A significant portion of the support for the publication and distribution of the IUCr Newsletter comes from advertising revenue. The average number of pages of advertising per issue rose from eight in 1996 to twelve in 1998.

The staff of the editorial office in Buffalo, New York, USA, are responsible for desktop preparation of all copy, all negotiations with the printer, postal authorities, and distribution houses, correspondence with contributors, maintenance and production of the mailing list, and solicitation and handling of all advertising.

The launching of this Series was reported to the General Assembly at Perth (1987). The agreement between the IUCr and the OUP was finalised soon afterwards. The Series has consisted of three sub-series:

IUCr Crystallographic Symposia (IUCr CS)

IUCr Monographs on Crystallography (IUCr MC)

IUCr Texts on Crystallography (IUCr TC)

The above arrangement continued over the initial seven years of the Series but was revised by the Executive Committee in 1994, when it was decided that, with the exception of the series on Crystallographic Computing, The Symposia Series (IUCr CS) could be dropped because it had become possible for that type of publication to be handled by Special Issues of the IUCr journals. Thus the Book Series consists now of Monographs and Texts only, except for the books on Crystallographic Computing.

The Book Series Committee membership currently is: P. Coppens (USA; Chair), A.A. Chernov (Russia), G.R. Desiraju (India), J. Drenth (The Netherlands), A.M. Glazer (UK), J.P. Glusker (USA) and J.R. Helliwell (UK), with M. Levitt as the ex officio representative of the OUP and the President and the General Secretary of the IUCr as ex officio members. This Committee considers proposals for new publications and makes recommendations to the IUCr Executive Committee and to the Delegates of the Press (the body responsible for approving all publications handled by the OUP).

During the reporting period the Committee interacted with a considerable number of prospective authors and with representatives of Oxford University Press (OUP). Collaboration with OUP has been easy and effective. While the Committee has attempted to facilitate rapid publication of approved manuscripts, there is a large variation in the length of time between the initial contact and publication, generally caused by circumstances beyond the Committee's control. Several volumes initiated by the previous Committee have appeared during the reporting period. Of the volumes handled by the present Committee, a Conference Proceedings and a Monograph are scheduled to appear before the Glasgow Congress. Two additional Monographs are under OUP contract and being written, while two other manuscripts are in the negotiating stage. The field of crystallography is by no means fully covered by the books that have appeared or are to appear in this Series. Prospective authors are invited to discuss their plans with any of the members of the Book Series Committee.

In 1996, the Executive Committee decided to set up a special Promotion Committee, with the aim of improving the financial position of the IUCr. The first task of the Committee was to appoint a Promotions Representative. As a result Miss A.J. Sharpe was appointed to this post in early 1998. Since then, a campaign to market the IUCr journals and services more aggressively to the crystallographic community as well as to structural science communities in biology, chemistry, materials science and physics has begun.

Increased participation at meetings, whether it be with an exhibition stand, the supply of promotional material for delegates' wallets, or as part of an informal joint marketing agreement with Oxford University Press, has raised the profile of the IUCr and its publications. An initiative to highlight journal articles within the IUCr Newsletter is designed to tempt individuals to petition their libraries for subscriptions, and an on-line order form now provides a convenient way to subscribe.

While it is important to promote all IUCr journals, particular attention has been given to the relatively new Journal of Synchrotron Radiation. Early results show that the number of personal subscriptions has risen owing to increased exposure at relevant conferences and users' meetings. The emphasis is now on increasing institutional subscriptions by targeting synchrotron and neutron sites. The imminent on-line appearance of Acta Cryst. Section D and the journal's recent redesign and doubling of frequency present exciting promotional opportunities for that publication.

Attractiveness and value in the market place are areas that need constant monitoring, and innovation is the buzzword for mature journals. Market research and competitor tracking may reveal ideas for new sections and presentation.

Special Issues, whether milestone-celebrating compilations or conference proceedings, are important in increasing the impact of a journal. They are, however, expensive to produce. The sale of advertising space and of extra copies of these issues via conferences and advertising campaigns in the journals, the IUCr Newsletter, and on the IUCr web site has gone some way to recovering costs.

To give some idea of the impact at this early stage of the Promotions exercise, the total advertising revenue generated (January 1998 to March 1999) is USD 50,694. Most of the income has resulted from the following Special Issues: SRI '97 Proceedings (May 1998 issue of Journal of Synchrotron Radiation) USD 10,940; Fiftieth Anniversary of Acta Cryst. and the IUCr (November 1998 issue of Acta Cryst. Section A) USD 20,340; CCP4 Proceedings (November 1998 issue of Acta Cryst. Section D) USD 5,607. Additional revenue has come from sales of the World Directory of Crystallographers database and mailing lists compiled from this (USD 2,152) and from the sales of Special Issues (USD 4,800).

The Promotion Committee membership is currently A.M. Glazer (Chair), F.H. Allen, P.W. Codding, M.H. Dacombe, W.L. Duax, H.D. Flack, S.R. Hall, J. Harada, S.J. Maginn, A.J. Sharpe (Promotions Representative) and P.R. Strickland, with the President and General Secretary of the IUCr as ex officio members.

Members of the Commission had opportunities to meet during various international conferences, the most important event being in Alpe d'Huez, France, during the Aperiodic '97 Conference which took place in August 1997. In the past three years, the Commission focused its work along three main directions: the establishment of standards for the publication of aperiodic structures; the organisation of international conferences and micro-symposia on the same topic; and, finally, the coordination of conference activities between different communities working in related fields of aperiodic structures.

The checklist for the publication of incommensurately modulated crystals appeared in Acta Cryst. [(1997). A53, 95—100]. This document, established by the Commission, was published following broad consultations with specialists in the field of incommensurate crystal structures. It contains numerous recommendations and suggestions to authors for the publication of refined structures described in the superspace group approach. This document can be consulted on the IUCr web site.

Work on the CIF dictionary of modulated structures is progressing. A version close to the final draft is already available on the web. The feedback of specialists working in the field of modulated structures will be required. Moreover, a preliminary database containing more than fifty modulated structures is currently being tested.

The Aperiodic '97 conference took place in Alpe d'Huez in August 1997. The members of the Commission participated actively in the preparation of the conference in the role of the International Advisory Board. During the conference, specialists from many different areas related to aperiodic crystal structures presented the current state of research in their respective fields of interest. The Proceedings of the conferences (edited by de Boissieu, Verger-Gaugry & Currat) have recently been published by World Scientific, Singapore (1998). The next Aperiodic conference will take place in Nijmegen, The Netherlands, in 2000.

Commission members contributed actively to the organisation of many sessions devoted to aperiodic crystals in various international conferences, in particular ECM-17, ECM-18 and the Glasgow Congress.

The coordination between the organisers of the International Conference on Quasicrystals and the Commission was also successful and resulted in a better calendar of future conferences.

During the Prague ECM, a Special Interest Group (SIG) on Aperiodic Crystals was officially established as one of the first four in the European Crystallographic Association (ECA). Many Commission members participated actively in the foundation of the group and are presently members of the steering committee. A web site dedicated to this particular SIG provides useful information on the topic of aperiodic crystals. This site is maintained and constantly updated with new information.

At the time of preparing these papers, no report has been received from the Chair.

The Commission promotes the study of electron density distributions in both real and momentum space by bringing together physicists, chemists and crystallographers in conferences, workshops and schools, and by initiating and executing projects. The web page (http://www.tuwien.ac.at/theochem/iucr/csmd.html) is linked to the IUCr home page and contains updated information on the activities of the Commission.

During the past decades several programs have been written to carry out multipole refinements of the electron density distribution. Comparison of the results showed qualitative differences and thus made limitations apparent. This has led to the initiation of a new project for a critical assessment of the multipole refinement method. Theoretical structure factors (at T=0) were used as a benchmark to test various schemes in order to determine whether or not the different refinement methods were able to recover the original data. These tests have been tried with or without the addition of statistical errors or temperature broadening to the theoretical structure factors.

The first report has been given at the Oxford Gordon Research Conference (see below) with a poster by Pillet, Souhassou, Lecomte, Schwarz, Blaha, Rerat & Lichanot.

The development of the program XD by an international team under the leadership of T. Koritsanszky has been accomplished successfully and versions of this program were sent to several groups for critical tests.

Since 1991 the MEM has received the full attention of the community served by the Commission. Some highly controversial results have been reported at several conferences since. There was inconclusive and rather diffuse discussion about the MEM project mainly concerning the basis used in MEM. No subject led to more heated discussions than this. The need for high-quality data became apparent for successful applications of MEM. Presently it is planned to supply a few data sets, both theoretical and experimental, in order to test MEM. They will probably be for Si, Al₂O₃ and MgCu₂ and will be made available on the web page. The first conclusion is that reliable results in precise electron density studies may be obtained if not flat prior probabilities are used.

This project focuses on the determination of the Fermiology via high-resolution synchrotron-based Compton scattering. The first step consists of standardising procedures for evaluating high-resolution Compton data. The ability of Compton scattering to contribute to the Fermiology of metallic systems is evaluated. Synchrotron-based instruments are to be combined with quantum mechanical calculations based on density functional theory. The experimental results obtained by different groups showed substantial differences, whereas on the theoretical side, quite different methodologies — FLAPW and KKR — yield highly similar results.

A unified quantum mechanical description of the electronic structure from experimental charge and momentum densities is attempted. The aim of the project is to investigate to what extent the combination of accurate experimental density data from both position and momentum space can enable a direct access to wavefunctions and density matrices for systems of increasing complexity. In addition to unifying position and momentum space, density matrices reveal the nature and range of chemical bonding. The possibility of obtaining information on the non-diagonal elements of the density matrix from coherent Compton scattering experiments adds to the value of the field.

Since bringing scientists from different disciplines together is one of the main objectives of the Commission, meetings play a major role in its activities. Several were organised either under the close guidance of the Commission, such as the triennial Sagamore conferences, or in some other form of cooperation, such as the Gordon Conference, or in an intermediate form of interaction.

1. The First European Charge Density Meeting

This meeting was organised by C. Lecomte and held at the Abbaye de Premontres (14—16 November 1996). Sessions included materials science, maximum entropy, high-resolution synchrotron data, electrostatics, modelling of charge density and transferability, extension of experimental work to large systems and theoretical calculations. This meeting started a new series to be held every three years.

This 'Computing School on Practical Aspects of Charge Density Determination' was held 15—18 September 1997 at FU-Berlin, Germany, and was organised by T. Koritsanszky and P. Luger. The meeting covered not only important aspects of experimental charge density determination but also theoretical considerations. It included practical aspects of data collection at low temperatures, data reduction and model refinements with emphasis on the interpretation of the results and detection of ambiguities in the procedure. Hands-on tutorials based on the XD program package were given.

The Sagamore Conference was held in Waskesiu (in Prince Albert Park, near Saskatoon, Saskatchewan, Canada), 27 July — 1 August 1997, and was organised by B. Robertson on behalf of the Commission. This meeting was more physics oriented and showed that the field of interest is still an excellent focal point for scientists of different disciplines. Progress was noted in all parts of the field: the theoreticians discussed beyond local density methods; experimentalists, coming from neutron sources and from synchrotron facilities, brought new results on magnetisation densities; and computational scientists hotly discussed maximum entropy methods. Good progress was made with the interpretation of the experimental results.

The Gordon Conference on Electron Distributions and Chemical Bonding was chaired by K. Schwarz and C. Lecomte. The meeting was organised at Queen's College in Oxford, UK, 30 August — 4 September 1998. About 72 crystallographers, theoretical chemists and physicists discussed experimental determination, quantum chemical calculation, and the interpretation and the use of electron density distributions. The area detectors, the use of the maximum entropy method and the contribution of electron diffraction raised much interest and heated discussions. The field ranged from bio-molecules to inorganic materials science applications. By electing two members of the Commission as organisers of the next conference, the participants made sure that the Gordon Conference fits nicely into the activities of the Commission.

The Second European Charge Density Meeting will be held in Sitges, Barcelona, Spain, 30 September — 2 October 1999 and will be chaired by E. Espinosa. The next Sagamore Conference will be organised by L. Dobrzynski and will be held in Poland, 1—5 September 2000. The next Gordon Conference will be organised by C. Lecomte and J. Spence in summer 2001, provided approval is obtained by the Gordon authorities. A satellite meeting to ECM-19 on Crystallographic Computing for Electron Density Analysis, chaired by N.K. Hansen, will be held in Nancy, France, 24—25 August 1999 (http://www.lc3b.u-nancy.fr/ecm19/).

The Commission met in Seattle during the Congress in its new composition to discuss the next Sagamore Conference. Other meetings were held at the Sagamore Conference in Canada, where it was decided to have the next Sagamore meeting in Poland. The fields of Multipole Refinements and Maximum Entropy, Magnetisation Densities, and Encounter of Theory and Experiment in Charge Density Studies were identified for Microsymposia at the Glasgow Congress (all honoured). At the Gordon Conference a proposal was made for new candidates and the next Chair. At all meetings the projects were discussed.

A Special Interest Group on charge spin and momentum densities of the European Crystallographic Association was approved at ECM-18, Prague, Czech Republic, thanks to D. Feil and other promoters. The Chair is P. Becker.

During the triennium the activities of the Commission were again directed to the organisation of international schools on crystal growth and characterisation for young scientists. An attempt to prepare a School on Epitaxic Growth in Trieste, Italy, in 1997, together with the International Centre of Theoretical Physics as co-organiser and sponsor, failed because of budget problems. In 1998 the Commission helped to organise the following two Schools.

(1) The Tenth International Summer School on Crystal Growth (ISSCG-10), Rimini, Italy, 1—6 June 1998. This school was organised by chairs R. Fornari (MASPEC, Parma, Italy) and C. Paorici (former Commission Chair, University of Parma, Italy) in connection with the Twelfth International Congress of Crystal Growth (ICCG-12), which was held 26—31 July 1998 in Jerusalem, Israel. The Commission was engaged in the lecturing programme with three former and two past Commission members as speakers. The school was sponsored and financially supported by the IUCr and other national and international institutions. It was attended by about 60 participants, mostly PhD students, from 19 countries. The lectures are collected in the book Theoretical and Technological Aspects of Crystal Growth, published by Trans. Tech. Publ. Ltd., Zurich (Materials Science Forum, Volumes 276-277, 1998).

(2) The First International School on Crystal Growth Technology (ISCGT-1), Beatenberg, Switzerland, 5—16 September 1998, was organised by H.J. Scheel (Lausanne, Switzerland) and T. Fukuda (Sendai, Japan). Three Commission members were engaged in the International Advisory and Programme Committee and contributed to the programme as lecturers. ISCGT-1 was sponsored and financially supported by the IUCr and other national and international institutions. It was attended by about 55 participants from 13 countries. The lecture notes of the 55 one-hour presentations and their extended abstracts are assembled in a voluminous book. The publication of the proceedings of this school is in progress.

Four Commission members attended the 12th International Congress of Crystal Growth (ICCG-12) in Jerusalem, Israel, 26—31 July 1998. They met during the congress and discussed two main topics: (1) candidates for the Commission Chair and Commission members for the triennium 1999—2001, and (2) an International School on Crystal Growth (ISCG) in Brazil. The latter point was discussed with R. Caram, University of Campinas, Brazil. It was decided to hold the ISCG on 18—24 July 1999 in Campinas, Brazil, with R. Caram as Chair and H. Klapper as Co-chair. The preparation of this School was the main activity of the Commission in 1999. The School is sponsored and supported by the IUCr by support for two lecturers under the Visiting Professorship Programme.

During the 12th International Congress on Crystal Growth, 26—31 July 1998, in Jerusalem, Israel, the Commission Chair attended the business meetings of the International Organization of Crystal Growth (IOCG). It was again agreed to continue the cooperation of the IUCr and the IOCG in fields of common interest, in particular in the promotion of international schools for young scientists. The essential agenda of the IOCG business meetings and their results are presented in the report on the IOCG (Appendix 24.5 to the Agenda).

The Commission recommended IUCr sponsorship for the following international schools and conferences: Tenth International Summer School on Crystal Growth (ISSCG-10), Rimini, Italy, 1—6 June 1998, and the Twelfth International Congress on Crystal Growth (ICCG-12), Jerusalem, Israel, 26—31 July 1998. In addition, the Commission contributed to the programme of the Glasgow Congress, by establishing two microsymposia on crystal growth.

In the triennium the Commission has been engaged in the following activities, presented in chronological order.

1. At the Seattle Congress the Commission sponsored an Open Session entitled 'General Advances and Application of Crystallographic Computing'. The session was organised by G.J. Kruger and P.E. Bourne and chaired by D. Viterbo.

2. The seventh IUCr-sponsored computing school took place in 1996 following the Seattle Congress. The school was organised by Commission members P.E. Bourne and K. Watenpaugh and took place in Bellingham, USA. The School attracted 106 attendees from 16 countries. Of these, 38 were either speakers or tutors. The School covered the latest developments in macromolecular crystallographic computing for all aspects of the experiment and subsequent structure analysis.

3. School Proceedings, provided to attendees in draft form and after the school revised by the speakers, were made available on the Commission's web site in March 1997. For the period March 1997 through the end of that year there were 27,090 hits on the web page. Recently, there were still several down-loads per day of individual papers.

4. The 1996 School Proceedings are in the final stages of being published. It has taken hundreds of hours of additional author volunteer effort and support from the San Diego Supercomputer Center (SDSC) to get them into a format acceptable to Oxford University Press. The cost of the Proceedings is being off-set by unspent funds raised for running the School.

5. An Open Session of the Commission has been organised for the Glasgow Congress, entitled 'Improved Accuracy through Software'. Invited speakers are J. Albertsson, H. Berman, C.M. Gramaccioli, B. McMahon and P.S. White. The session was organised by all members of the Commission and will be chaired by P.E. Bourne.

6. The 1999 Computing School 'Frontiers in Computational Crystallography' will be held in Hixton, near Cambridge, UK, following the Glasgow Congress. G. Bricogne and D. Watkin are organising the School.

Enhancements to the Commission's web site to include reports, Proceedings of the 1996 School and forthcoming events have been made throughout this period. Little progress has been made on the charge of providing high quality standard data sets that would be used by software developers to validate their work. Available information was to include experimental data derived from powders and single crystals of inorganic and organic compounds, including proteins at various resolutions. Results derived from using these data by different software programs would also be available. Users would be able to obtain all data and results from the Commission's web site and from CD ROM. It is hoped that the incoming Commission will take up this charge.

The Commission met in Seattle shortly before the Congress opened; all its other work throughout the triennium was accomplished either electronically or by 'snail-mail', with the following exception. Several members of the Sub-committee on the Nomenclature of n-Dimensional Crystallography met in person in July 1997 in Nijmegen, The Netherlands, in December 1997 in Paris, France, and in August 1997 in Geneva, Switzerland. Membership in the Commission is entirely ex officio, by virtue of a primary IUCr responsibility closely related to crystallographic nomenclature. Six new members joined the Commission following appointment either as Editor of an individual Volume of International Tables for Crystallography, as Chair of the Committee for the Maintenance of the Crystallographic Information File Standard (COMCIFS), or as Chair of the IUCr/OUP Book Series Committee. As in prior triennia, the work of the Commission was conducted primarily through the expert sub-committees and working groups it appoints. All recommendations arising thereby are reviewed by the Commission.

The Sub-committee on Atomic Displacement Parameter Nomenclature completed its 1994 charge of examining the merits of a uniform approach in reporting quantities that describe atomic displacement with a report entitled Atomic Displacement Parameter Nomenclature, which was published in Acta Cryst. (1996). A52, 770—781. Following a consideration of the inconsistent terms and symbols previously used for parameters denoting dynamic or static displacements of atoms in crystals, the report provides clear definitions for these quantities, discusses graphical representations of the Gaussian mean-square displacement matrix and the expressions used if the Gaussian approximation is inadequate, and makes recommendations for symbols and nomenclature. It, as all other Commission reports, is now fully accessible on-line at the Co