Structural, elastic, and electronic properties of compressed ZnP2

The structural, elastic and electronic properties of compressed ZnP2 were investigated by first-principles total energy calculations. The optimized equilibrium structural parameters agree well with those of experiments for α-ZnP2 and β-ZnP2 at zero pressure. α-ZnP2 transforms into I41/22 phase (referred as γ-ZnP2) at 11 GPa, which is an indirect band-gap (∼0.78 eV) semiconductor. Space group of low pressure phase is the subgroup of that of high pressure phase. The calculated elastic constants for α-ZnP2 and β-ZnP2 at zero pressure as well as γ-ZnP2 at phase transition pressure determine their stability mechanically. Phonon calculation confirms dynamical stability of γ-ZnP2.