First-principles calculations of phase transition and bulk modulus of PtC

Abstract

First-principles plane-wave pseudopotential density functional theory method with the ultrasoft pseudopotential scheme in the frame of the GGA correction is performed to calculate the phase transition and the bulk modulus of the PtC. The phase transition from zinc-blende structure to rock-salt structure occurs at the pressure of 475 kbar. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the dependences of cell volume and lattice constant on temperature at 0 pressure, the isothermal bulk modulus and its pressure derivative on pressure along the isotherms 0, 500, 1000, 1500, 2000, and 2500 K, are also successfully obtained.