Theoretical study of possible iridium ditelluride phases attainable under high pressure

We examined the feasibility of preparing new high-pressure polymorphs of Ir Te2 by determining the relative energies and unit cell volumes of known and hypothetical forms of IrTe2 on the basis of first-principles electronic ba nd structure calculations using the Vienna ab initio simulation package (VA SP). The IrTe, polymorphs included in our analysis are three known phases, i.e., the polymeric CdI2-type, pyrite-type, and monoclinic IrTe2 phases, as well as four hypothetical phases, i.e., ramsdelite-type, pyrolusite-type, IrS2-type, and marcasite-type phases. The charge balances of these IrTe, ph ases were analyzed by carrying out extended Huckel tight-binding electronic band structure calculations for the crystal structures optimized by VASP c alculations. (C) 2001 Academic Press.