Evaluation of reflection intensities for the components of multiple Laue diffraction spots. II. Using the wavelength-normalization curve

Abstract

In a Laue diffraction pattern, 10-20% of the spots result from the exact superposition of two or more reflections that are 'harmonics', e.g. hkl, 2h,2k,2l etc. The use of only the 80-90% of the reflections measurable as singles may not always be sufficient and evaluation of the intensities of the components of the multiple spots is therefore important. A procedure for this deconvolution is given, based on the varying nature of the wavelength-normalization curve. A feasibility trial has been carried out using a single Laue diffraction image of tetragonal hen egg white lysozyme (HEWL) recorded on an image plate. This allowed the intensities of 103 reflections to be evaluated from multiple spots. For these reflections, their agreement with monochromatic diffractometer data gave an R factor of 0.157 for 96 common reflections. An earlier paper described another procedure based on direct methods, which addressed the same problem.