Improvement of the Inorganic Crystal Structure Database ICSD

The ICSD, published by Fachinformationszentrum Karlsruhe, now contains about 60,000 structures, including about 10,000 mineral structures. A new retrieval program written by NIST, USA under Windows will be delivered at the end of May 02 (with updates 2/2001 + 1/2002) together with VISUAL for structure drawing and powder pattern calculation and a program for calculating atomic distances and bonding angles. New is the field “mineral group”, which also can be searched for. A field “structure type” is prepared but not yet activated. Also the calculated density Dx is given and the numbers are not rounded as before.

My first work for ICSD after my retirement in 1996 was updating the minerals. About 4,000 mineral names were missing, even if the structures themselves were in ICSD. Then about 900 structures with misprints in their publications could be corrected, the most often errors being missing signs, missing leading zeros, interchanged digits, and wrongly doubled digits (for instance: .133 instead of .113), an error very difficulty to be detected in proof-reading. Further errors were wrong origins of unit cells (most often in P212121), wrong space groups, transformed coordinates with non-transformed unit cells, and missing cell parameters b for monoclinic cells. Another problem are the correct constraints for anisotropic displacement parameters, especially in trigonal and hexagonal space groups. If possible, cross references to the Powder Diffraction File PDF for new and revised entries are given (shall this be continued as it is now very easy to get calculated powder patterns immediately?). During the last four years I added about 9,500 overlooked or forgotten structures published in 1913-1990. To my experience about 15 % of the structures were missing. Now this should be reduced to about 1 %.The best way for finding forgotten structures would be by assistance of the authors themselves. Authors, please, check your publication lists against ICSD and send me reprints of the missing papers!!! If your list contains more than 50 inorganic structures, I am willing to do this for you: just send me your publication list.

Another reason for missing structures is their non-publication. Nearly half of all structures presented at meetings like this will never be published in full. If the abstract (without coordinates) can be cited, you may send me this together with the full data set for inclusion in ICSD (there with the remark: “Atomic parameters from author”). Also unpublished structures are contained in a large number of Dr.-theses.

Part of my further work will be the filling of the field “structure-type”, which is not yet possible. This field will use the formula of a representing compound, e.g NaCl(-type), together with an entry number where more details of the structure-type can be found (e.g. B1-type) and which contains the cell and coordinates in a standard setting. Momentary I add the phase transitions of P. E. Tomaszewski (Phase Transitions 38 (1992) 127-220) to already existing entries.

Another problem are the different spellings of author names, e.g “Hladyshevsky” as published in an Ukrainian text and “Gladyshevskii” in Russian. What to do? The Chinese usually write their family name first. So some abstractors have interchanged family and calling names. As all these names are short, the best would be to give the Chinese names in full, not abbreviated. Only by doing so, one may get the publication list of one distinct author only.

Rudolf Allmann, Marburg