Section 24.3.4.2. IsoStar: a library of knowledge about intermolecular interactions

IsoStar (Bruno et al., 1997) is based on experimental data, not only from the CSD but also from the PDB, and contains some theoretical results calculated using the ab initio intermolecular perturbation theory (IMPT) method of Hayes & Stone (1984). The experimental data in the CSD and the PDB have been used to display interaction geometries involving central groups (A) and contact groups (B). CSD search results of the type exemplified above are transformed into an easily visualized form by overlaying the A moieties. This results in a 3D distribution (scatterplot) showing the experimental distribution of B around A. A web-browser front end permits rapid access to these scatterplots, which can be viewed in RasMol (Sayle, 1996), interrogated interactively, converted into contoured surfaces etc.

Version 1.1 of IsoStar, released in October 1998, contains information on non-bonded interactions formed between 310 central groups and 45 contact groups. Version 1.1 contains over 12 000 scatterplots: 9 000 from the CSD and 3 000 from the PDB. IsoStar also reports results for 867 theoretical potential-energy minima calculated using the IMPT procedure. The library will be updated on a regular basis using automated software procedures developed at the CCDC.

Chapter 22.4 contains illustrative examples from IsoStar, together with a more complete description of the knowledge base and its applications.