dSNAP: new software for analysing the results of cambridge data base searches

Cambridge Structural Database (CSD) searches can produce thousands of ’hits’ especially if a simple fragment is used, and as a result, processing and interpreting the results becomes a considerable task, and one in which it is easy to make mistakes. Cluster analysis using dendrograms, metric multidimensional scaling and suitable visualization tools can reduce the workload to a few hours withminimal user intervention, and thusminimal user bias. The real beauty of the method is in its interactivity and scalability: it allows you to go from an overview of the entire dataset and easily spot any outliers or errors, to the ability to ‘drill down’ within a cluster, looking atmore andmore detailed differences between different fragments in a statistically rigorous way. The formalism and the associated program are also invaluable in crystal engineering and structure prediction environments since it can readily identify the basic motifs in a structure and how they pack in the unit cell. The computer program we have developed to do this is dSNAP [1]. It is available free of charge from the web site http://www.chem.gla.ac.uk/snap.