Crystal structure of Hg2PCl2 and electronic structure of its main "building unit" - The (P2Hg6) octahedron

The crystal structure of Hg2PCl2 (I) has been determined based on single cr ystal diffraction data. I crystallizes in a monoclinic space group I2/m, (N o. 12, a nonstandard setting), 7.643(6) Angstrom, b = 7.977(2) Angstrom, c = 8.539(6) Angstrom, beta = 115.23(3)degrees, Z = 4, R = 0.0526, wR(2) = 0. 1345. Its crystal structure is based on the (P2Hg6) octahedron. Such octahe dra share four corners out of six, forming a layer. The arrangement of the layers follows that of the K2NiF4 structure type. Relations of the structur e of I to the structures of similar cadmium and mercury pnictidehalides are discussed. Some details of the electronic structure of I are discussed bas ed on the molecular orbital calculations performed on a model (P2Hg6)(8+) c ation. (C) 1999 Academic Press.