
A computer program to calculate the contributions of crystal, capillary and a simple model of mother liquor to the overall absorption of X-rays has been written. It is based on the Gaussian quadrature method of integration; the crystal is described by the polyhedral faces bounding it, the capillary by its diameter, thickness and orientation with respect to the diffractometer axes and the mother liquor by the crystal faces that trap it between crystal and inner capillary wall. The program is written in Fortran for a VAX 11/780 computer and incorporates tables of mass absorption coefficients for silver, molybdenum and copper radiations for easy calculation of linear absorption coefficients.