E0210

An Introduction to SnB v2.0: A Cool Way to Solve Structures (or How to Beat the Heat in Washington, D.C.). Russ Miller and Charles M. Weeks, Hauptman-Woodward Medical Research Institute, 73 High Street, Buffalo, NY 14203-1196 USA

Shake-and-Bake is a direct methods procedure that alternates reciprocal-space phase refinement with filtering in real space to impose constraints. SnB is a publicly available program based on the Shake-and-Bake methodology. The program employs a multi-trial approach in which initial trial structures typically consist of randomly positioned atoms, phase refinement is based on either the traditional tangent formula or on an optimization procedure that exploits a parameter-shift algorithm, and density modification in real space typically takes the form of peak picking.

SnB v1.5 has been available for several years and is being used regularly in many laboratories. This workshop serves as the springboard for SnB v2.0, which is expected to be available for download via the SnB Web site and for direct access via the new SnB Computational Web Site by the time of the Workshop. Feel free to visit www.hwi.buffalo.edu/SnB/. SnB v2.0 was constructed in an effort to (a) improve the overall performance of the Shake-and-Bake procedure, (b) provide a modern Graphical User Interface (GUI), (c) provide a dynamic histogram facility for evaluating the potential for solving a structure under consideration, (d) provide an easy means for porting to a variety of platforms (Unix workstations, PCs, multiprocessor machines, networks of machines, etc.), (e) correct deficiencies in the handling of atoms on special positions, (f) provide access to an integrated data processing facility, and (g) provide an interactive graphical visualization tool that can be used to steer refinement.

This research was supported by grants NIH GM-46733 and NSF IRI-9412415.