A test for the computer-aided generation of the Cambridge Connectivity Files

A computer program has been developed to generate the Cambridge Connectivity File from more fundamental files, the Bibliographic and the Structural Data Files, considering that a complete set of numerical crystallographic data defines the structural formula of that compound. The program derives all the items recorded in the Connectivity File. The bond type and the net atomic charge are assessed by use of the bond orders calculated from the interatomic distances. Hydrogen atoms not given in the atomic coordinate list are recovered. Ring structures including aromatic rings are identified and recorded through the ring-search procedure. A test of the program on the 283 compounds in the sample tape suggested that this procedure will be useful in generating the Connectivity File. It also implied that a slight modification in the definition of the bond type and the net atomic charge would improve the usefulness of this method.