Number 12 - November 1999

ICSD USER'S GROUP NEWSLETTER
(Inorganic Crystal Structure Database)

edited by

I.David Brown
Brockhouse Institute for Materials Research
McMaster University
Hamilton, Ontario, Canada L8S 4M1

1. Summary of the Session on Innovative Uses of the Inorganic Crystal Structure Database in Glasgow

A special session on Innovative Uses of the Inorganic Crystal Structure Database (ICSD) was held during the IUCr Congress in Glasgow, giving the large audience a flavour of the kind of power we can expect to find in retrieval systems for the ICSD during the next few years.

The session started with a description by Heinrich Behrens of the new management arrangements under which the ICSD is being maintained by the Fachinformationzentrum Karlruhe (FIZ) in Germany with software being written by Vicky Karen at the National Institute for Science and Technology (NIST) in the USA (see 2. below for more details). Innovative uses of the database were described by Sidney Abrahams, who showed us how to find new ferroelectric materials by searching the ICSD for polar structures that are close to having a center of symmetry, and by Michael Berndt, standing in for Günter Bergerhoff, who described how a derived database of standardized structures can be used to find compounds with similar structures.

Two databases related to the ICSD were described with a mouth-watering account of the kinds of searches that will be possible with their retrieval software. John Rodgers talked about the CRYSTMET file of metal structures and Michael Berndt described progress with the Pauling File which currently contains information on the structures and properties of binary compounds but which will be extended to include all inorganic and metallic compounds by 2007.

The Powder Data File (PDF) has been extended by including some 40,000 new powder patterns calculated from structures in the ICSD and John Faber showed how easy it was to search this part of the PDF for groups of compounds that shared interesting properties. Finally, Alan Hewatt gave us a glimpse into what state-of-the-art retrieval software looks like with a demonstration of his web version of the ICSD.

We all came away from the session with the feeling that, after struggling for nearly 20 years, the ICSD was about to take on a new life. With the new user-friendly software that is becoming available it will not be long before we are able to exploit the database in ways that most of us can still hardly imagine.

(David Brown)

2. ICSD New Developments

Dr. Behrens has supplied us with a summary of his talk in which he describes the current status of the database and plans for its future.

I. Introduction

The Inorganic Crystal Structure Database (ICSD) is now produced cooperatively by FIZ Karlsruhe and the National Institute of Standards and Technology. Components of the ICSD System are:

• Archival and derived data
• Analysis / Evaluation software
• Retrieval / User interface
• Applications software

• ICSD on CD-ROM for PC
  DOS-based RETRIEVE
• ICSD on Intranet
  Web version based on CRYSTIN
• ICSD Online
  STN International
  Web demo version: http://www.fiz-karlsruhe.de/fiz/products/icsd.

• Currency
• Addition of missing retrospective data
• Specific evaluation of existing data
• Completely new PC-software
• Completely new production software
• Web offer

II. Data

As far as the content of the database is concerned the present situation looks as follows:

• Currently the database contains: 50,479 entries
• It is updated with approximately: 2,500 new entries per year

a) Incorporation of Missing Structures

• Additional material supplied by users or found by ICSD staff is regularly collected and incorporated in ICSD (about 140 entries per year).
• In a special effort, however, more than 1000 entries with retrospective data were detected, added and processed for the forthcoming update in the last and this year.

b) Evaluation and Correction of Data

• Errors supplied by authors and users are always corrected at regular intervals.
• In a special program, about 10,000 specific entries have been systematically and intellectually reviewed by an expert (Prof. Allmann, University Marburg) in the last three years. Corrections were made if necessary. Most of the entries reviewed relate to minerals.

III. Software

The current software systems which are used in combination with ICSD are:

• CRYSTIN (Fortran) which is applied for the production of the database and is the basis for the WWW offer.
• RETRIEVE (DOS only) combined with the VIZUALIZER for PC applications.

Let me now come to some details relating to the PC software. Present and future special retrieval features of the PC software are:

a) Search menus which include:

• Selection of structures with a distinct chemical composition
• Lattice-based searching using reduced cells (this will be available in the new software only)
• Symmetry information (crystal system, space group, Pearson symbol, etc.)
• Many other searches (bibliographic data, mineral names, cell volume, etc.)

• 3-dimensional visualization of structures
• Powder pattern simulation
• Calculation of interatomic distances and angles
• Standardization of entries
• Comparison of two isopointal entries.

Examples of new search features in the Windows-based PC software are:

• Search for reduced cell
• Separate search for mineral group and mineral name
• Search for PDF numbers
• Search for calculated density (and molecular weight) for all compounds
• Up to 10 answer sets storable and combinable by Boolean logic
• Free text search in the whole database
• Improved powder pattern simulation.

IV. Conclusion

ICSD is produced in a long-term partnership of FIZ and NIST and will continuously be improved in many aspects. Both partners put emphasis on:

• Commitment to excellence in inorganic structural data
• Recognizing the Web is the future
• Working with the Crystallographic and Materials communities to offer the functionality needed.

3. Versions of the ICSD currently available

ICSD is currently offered via the following channels or software systems respectively:

• RETRIEVE (DOS only) combined with the VIZUALIZER for PC application
• Web version combined with XTAL-3D vizualizer and powder diffraction simulation. Available for UNIX platforms (SUN, HP, SGI). Also available as Intranet version.
• CRYSTIN command oriented Fortran version for UNIX systems
• ICSD Online on STN International

4. Where to Send Additions and Corrections to the ICSD

Any additions or corrections to the database should be sent to:

Dipl-chem. Volker Greiner
Fachinformationszentrum-Karlsruhe
D-76344 Eggenstien-Leopoldshafen
Germany

Phone: (49) 7247 808 262
Fax: (49) 7247 808 666
email: vg@fiz-karlsruhe.de