The elastic and thermodynamic properties of new antiperovskite-type superconductor CuNNi3 under pressure

The crystal structural, elastic and thermodynamic properties of antiperovskite-type superconductor CuNNi3 under pressure are investigated by using the density functional theory within the generalized gradient approximation (GGA). The ground-state properties are found to agree with the available experimental data and others theoretical results. The elastic constants, shear modulus and Young׳s modulus, Debye temperature, melting point and minimum thermal conductivity under pressure are calculated, the results show those properties increase monotonically with increasing pressure. Finally, the ductility of CuNNi3 was analyzed using the B/GB/G ratio, Cauchy pressure and Poisson׳s ratio σσ.