Crystal database

Cruz-Cabeza, A.J. and Groom, C.R. (2011) Identification, dassification and relative stability of tautomers in the Cambridge Structural Database. Crystal Engineering Communications, 13, 93-98. 

Cambridge Structural Database Crystal Structure Calculations 2 Force Fields A Brief Introduction Force Fields A General Discussion Free Energy Calculations Methods and Applications Free Energy Perturbation Calculations Free Energy Simulations Geometry Optimization 1 Geometry Optimization 2 Symmetry in Chemistry. 

Cambridge Structural Database Crystal Structure Calculations 1 Intermolecular Interactions by Perturbation Theory X-Ray Crystallographic Analysis and Semiempirical Computations. 

The two major databases containing information obtained from X-ray structure analysis of small molecules are the Cambridge Structural Database (CSD) [25] and the Inorganic Crystal Structure Database (ICSD) [26] both are available as in-house versions. CSD provides access to organic and organometallic structures (mainly X-ray structures, with some structures from neutron diffraction), data which are mostly unpublished. The ICSD contains inorganic structures. 

ICSD is a numeric database with 65 000 inorganic crystal structures (December,... 

The Cambridge Structural Database (CSD) contains crystal structure information... 

The Cambridge Structural Database (C5D) and the Inorganic Crystal Structure Database (ICSD) contain information obtained from X-ray structure analysis. 

Powder diffraction patterns have three main features that can be measured t5 -spacings, peak intensities, and peak shapes. Because these patterns ate a characteristic fingerprint for each crystalline phase, a computer can quickly compare the measured pattern with a standard pattern from its database and recommend the best match. Whereas the measurement of t5 -spacings is quite straightforward, the determination of peak intensities can be influenced by sample preparation. Any preferred orientation, or presence of several larger crystals in the sample, makes the interpretation of the intensity data difficult. 

Another recent database, still in evolution, is the Linus Pauling File (covering both metals and other inorganics) and, like the Cambridge Crystallographic Database, it has a "smart software part which allows derivative information, such as the statistical distribution of structures between symmetry types, to be obtained. Such uses are described in an article about the file (Villars et al. 1998). The Linus Pauling File incorporates other data besides crystal structures, such as melting temperature, and this feature allows numerous correlations to be displayed. 

Allen FH. The Cambridge Structural Database a quarter of a million crystal structures and rising. Acta Cryst B 2002 B58 380-8. 

It is important to emphasize that this lattice database is highly idealized compared to real databases. Unlike the lattice database, real databases cannot be treated as thermodynamic ensembles of protein-ligand complexes equilibrated at room temperature [33,34]. Two of the more straightforward reasons are mentioned here. First, real databases are inherently biased toward strong binders (K < 10 pM), because weak binders are difficult to crystallize and of lesser interest. Second, as mentioned above, real databases are not composed of a representative selection of proteins and ligands, and their compositions are biased toward peptide and peptidomimetic inhibitors and certain protein superfamilies. In contrast, because only one protein and four ligand types are used, the lattice database should have representative ligand compositions. 

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