A KNOWLEDGE BASE OF DERIVED INFORMATIOM FROM THE CAMBRIDGE STRUCTURAL DATABASE: NON-BONDED INTERACTIONS. Jason C. Cole, Frank H. Allen, Jos P. M. Lommerse, R. Scott Rowland, Robin Taylor, Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge, CB2 1EZ, UK

Databases provide users with easy access to a large amount of experimental data. Because of this, exploration of variations in experimental features as a result of different conditions is possible.

The Cambridge Structural Database (CSD) is an example of such a database. It has already been used to derive mean experimental bond lengths and angles for a large number of distinct chemical moieties. Such data is probably as important as the CSD itself and so also needs to be easily accessible to chemists in a so-called "knowledge base".

Because the CSD is a crystallographic database, it can be used to explore "non-bonded" interactions as well as covalent interactions. We are currently developing a knowledge base of non-bonded interactions. It will convey information about both the types and directionality of non-bonded interactions for a wide selection of pharmaceutically interesting functional groups. The informtion will be presented as scatterplots and "vector"plots around the varying functional groups. These plots will be fully importable into molecular modelling packages (e.g. SYBYL). It is hoped that the information will assist in interactive ligand design. The data may also assist in parameterizing automated ligand docking programs.

The knowledge base will also contain theoretical results for some non-bonded interactions generated from Intermolecular Perturbation Theory (IMPT). This method is suited to calculations on molecular complexes since the energies produced are free of basis set superposition error.

In this talk, some of the generated data will be presented, along with an introduction to the menu-based system that will be utilised to access the data.