LSCALE - The new normalization, scaling and absorption correction program in the Daresbury Laue software suite

Abstract

A new program in the Daresbury Lane software suite has been developed for the scaling and normalization of Laue intensity data, to yield fully corrected structure amplitudes. Previously available routines have been improved, and additional options for refinement, control and statistical diagnostic output provided. A new feature, namely a wavelength- and position-dependent absorption correction that models a two-dimensional surface derived from the Laue data alone, is discussed in detail; it is tested on simulated and real data, and the improvement in data quality is demonstrated. The wavelength normalization function is now able, when sufficiently redundant experimental data are available, to model fine details such as the features arising from the modification of the incident intensity spectrum by a platinum mirror in the beamline optics. A full data set for tetragonal lysozyme is processed with the new program, and extensive statistical output is given. © 1999 International Union of Crystallography - all rights reserved.