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

► The phase transition from zinc-blende structure to rock-salt structure of the recently high-pressure synthesized compound PtC has been investigated. ► We have given the relationship between bulk modulus B of ZB-PtC and temperature T at 0 pressure. It is the rapid volume or lattice parameter variation that makes the bulk modulus B rapidly decreases. ► At an extended pressure and temperature ranges, the isothermal bulk modulus and its pressure derivative of PtC with ZB structure are predicted by using the quasi-harmonic Debye model.