CORRECTION FOR ABSORPTION AND BEAM INHOMOGENEITY IN X-RAY SINGLE-CRYSTAL DIFFRACTOMETRY - METHOD OF ANALYTICAL INTEGRATION

A computational method of absorption correction in X-ray diffractometry for single crystals in the shape of convex polyhedra bathed in an inhomogeneous and in a homogeneous X-ray beam is suggested. An absorption correction is calculated for each reflection of the data set using the measured coordinates of the specimen vertices and the experimentally measured intensity distribution in the primary beam. The program ABSCOR is written in Fortran and may be readily adopted to any four-circle diffractometer and data format. The results of the method described for crystals of different dimensions and different absorption coefficients are given. It is shown that beam inhomogeneity strongly influences the reflection intensity of large non-isometric crystals.