STRATEGY: a program to optimize the starting spindle angle and scan range for X-ray data collection

STRATEGY is a program for determination of the optimal starting spindle angle and scan range for X-ray diffraction data collection. It is optimized for crystals of macromolecular compounds using a one-circle diffractometer with a two-dimensional detector. In its current implementation, the program reads the starting crystal orientation and cell parameters from a DENZO intensities `.x' file and simulates all the reflections that can occur during a 360° rotation of the crystal. It determines whether the reflections can be recorded on the detector and sorts them on spindle angle. Then it gives diagrams representing the needed sweep as a function of the starting spindle angle for different degrees of completeness of the data set wanted, and produces redundancy tables for the shortest data collection possible for each desired completeness. Use of the program assists in careful planning of data collection: it will assure a complete data set, and certainly will allow data collection in the shortest possible time, sometimes reducing the data-collection time by a factor of two or more, depending on the lattice symmetry and the data-collection mode.