Crystallographic databases and their uses

Information that is put into this Database is derived from published reports of crystal structure determinations. The data extracted from the scientific literature in this way include the atomic coordinates, information on the space group, chemical connectivity, and the literature reference to each structure determination. Each compound listed in the Database is identified by a six-letter code (the REFCODE), unique to each crystal structure determination. Duplicate structures and remeasurements of the same crystal structure are identified by an additional two digits after the REFCODE. Scientific journals are scanned regularly by the Database staff for reports of crystal structure determinations, and the data are then entered into this Database. Structural data are also deposited by journals, for example. Chemical Communications, that publish articles, but do not have space for atomic coordinates. All crystallographic data reported in the literature are tested by the Database staff for internal consistency, precision, and chemical reasonableness. In 

The Cambridge Structural Database may be searched in several ways. It is possible to find reported three-dimensional structural data on all compounds in a given class (such as steroids or peptides). It is also possible to search for compounds by name or portion of name. For example, 

FIGURE 16.3. Input and output from the Cambridge Structural Database. Morphine has been chosen as an example, (a) Search for the crystal structure of morphine. This can be done by name, atomic connectivity, or REFCODE (as in this example). The input was simply the first three lines shown above. The output follows (at REFC ) and includes the journal reference, space group, unit-cell dimensions, R factor, etc. (b) Output of atomic coordinates from the input at the top of (a). Courtesy the Cambridge Structural Database. 

FIGURE 16.3 (cont d). Output from the CSD. (c) Molecular formula and three-dimensional diagrams generated from search, (d) Geometric searches leading to, for example, histograms of comparisons of numerical output. Courtesy the Cambridge Structural Database. 

AUTH H.L.CARRELL.J.P.GLUSKER,V.BURGER,F.MANFRE,D.TRITSCH 

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