Tcl/Tk-based programs. III. CRITXPL: graphical analysis of the X-PLOR refinement log files

# 1999 International Union of Crystallography Journal of Applied Crystallography Printed in Great Britain ± all rights reserved ISSN 0021-8898 # 1999 de®ned by the data-processing programs. In the calculated positions, it displays the logarithm of the diffraction intensity or amplitude of each reciprocal-lattice point with radius and degree of darkness according to the input values. Any planes of the reciprocal lattice can be displayed. When the index and amplitude or intensities (h, k, l, F or I ) of all the re ections are read, the program produces pictures very similar to real precession photographs.