The crystal structure of IV-VI compounds. I. Classification and description

It is shown that the crystal structures of the binary IV-VI compounds can be classified by parameters derived from a Pauli-force model potential, which has previously been used successfully for the octet and suboctet materials (ANBP-N with P=8 and 2<or=P<or=6). Trends in the transverse effective charges, in the heats of formation, in the energy gap between bonding and antibonding states, and in bond angles and bond lengths can also be explained with these parameters. The author discusses the origin of these correlations in terms of the band structure and atomic pseudopotentials, and demonstrates how a microscopic analysis of the crystal structure leads towards a quantitative understanding of the cubic to rhombohedral phase transition in the (Ge, Sn)Te system.