Ab-initio approach to IrO2 polymorphs – properties at high pressures

The present paper reports the structural and lattice dynamical study for iridium dioxide (IrO2) at ambient and higher pressure conditions up to 60 GPa. Total energy calculations are carried out using first principle density functional theory. The ground state properties like lattice constant, bulk modulus are calculated and are in good agreement with theoretically and experimentally reported values. The band structure calculations confirm the metallic character of IrO2. The analysis of calculated phonon dispersion curves illuminates the structural systematic and the nature of phase transitions under the influence of pressure.