The Bilbao Incommensurate Structures Database

This database is dedicated to incommensurate modulated and composite structures. Commensurate structures described in the superspace formalism are also included.

The database currently hosts 145 entries (of which 24 are composites). (Show all entries)

You can search through these entries using the search form. You can also validate your structures in CIF format, and/or submit them to the database.

This initial database includes mainly structures published in Acta Crystallographica since the search engine at Chester allowed us a rapid collection of the papers.


Some structural parameters have been modified to fulfill the recommendations of the IUCr (for instance thermal displacement parameters in Beta form are not allowed) and to get a unified description of the modulations which permits an easy and safe manipulation of the stored data.
In general the structures are described using the superspace formalism. Modulations can be parameterized according to the different functions in use.


The structural data is saved in CIF format based on the CIF core dictionary and on the the CIF dictionary for modulated structures, plus some extensions, if required.

Apart from the web interface form, CIF files can also be used for importing data to the database.

The stored CIFs have been checked for consistency and typos. However, errors due to a bad interpretation of the published data or undetected typographic mistakes may still be there.

Authors are strongly encouraged to revise their data

Please send your comments about this site to: administrador.bcs@ehu.es