EVALUATION OF REFLECTION INTENSITIES FOR THE COMPONENTS OF MULTIPLE LAUE DIFFRACTION SPOTS BY THE MAXIMUM-ENTROPY METHOD

In a Laue diffraction pattern, 10-20% of the spots result from the exa ct superposition of two or more reflections that are 'harmonics'; a hi gh proportion of these are low-resolution reflections. For the solutio n of large or difficult structural problems, the intensities of the re maining 80-90% of the reflections, measurable as singles, may not be s ufficient and thus the evaluation of the intensities of the components of the multiple spots is important. A new method for this deconvoluti on is presented that is based on maximizing the entropy of the Patters on function subject to the constraints imposed by the observed intensi ties of single and overlapping reflections. This method does not requi re data redundancy and therefore is of particular interest for time-re solved studies on a short time scale. A new computer program (ME) was implemented and tested with Laue diffraction data from hen egg white l ysozyme. The R factor between the deconvoluted reflection intensities from Laue multiple spots and observed intensities from monochromatic d ata was 0.116.