First-Principles Study on the Elastic Properties of Platinum Nitride

Elastic properties of platinum nitride (PtN) are studied by first-principles calculations with the fully relativistic full potential linearized augmented plane-wave (LAPW) method, the plane-wave ultrasoft pseudopotential (PW-PP) and the projector-augmented wave (PAW) methods. The results reveal that: (1) the scalar relativistic scheme is sufficient to treat the valence electronic structure, i.e. the spin-orbit effect has little effect on the bulk modulus value of platinum nitride; (2) the all-electron full potential method is no more accurate than the pseudopotential and PAW-based methods when calculating the lattice constant and bulk modulus properties of the platinum nitride; (3) platinum nitride in zinc-blende structure is unstable and its crystal structure is still an open problem.