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 spindl e angle and scan range for X-ray diffracton data collection. It is opt imized for crystals of macromolecular compounds using a one-circle dif fractometer with a two-dimensional detector. In its current implementa tion, the program reads the starting crystal orientation and cell para meters from a DENZO intensities '.x' file and simulates all the reflec tions that can occur during a 360 degrees 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 redundan cy tables for the shortest data collection possible for each desired c ompleteness. Use of the program assists in careful planning of data co llection: 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 lat tice symmetry and the data-collection mode.