The Single Crystal Vs. The Powder Method for Identification of Crystalline Materials

Abstract

Single crystal X-ray diffraction methods for the study of crystalline materials, although reliable, have been, mainly confined to the academic laboratory because of the rather lengthy and complex procedure necessary to determine the unit cell and the space group. The situation has now changed. Several recent developments give single-crystal methods considerable potential for routine Industrial use. They Include growth of the data base, advances in lattice theory, and automation of the single-crystal X-ray diffractometer. To identify an unknown, one can start with a single crystal, mount it on the diffractometer, determine a refined primitive cell, reduce the cell, and check against a file of known reduced cells. The entire procedure can be automated. As a result, the single-crystal X-ray diffraction method can now complement the powder method for the routine analysis of crystalline materials.