The thermodynamic properties of the boron pnictides were calculated from the phonon frequencies using the statistical thermodynamic approach on a high-precision sampling mesh in the Brillouin zone. The temperature dependencies of heat capacity at constant volume (C v ) and entropy (S) of zinc-blende and qtz BAs are shown in Fig. in comparison with experimental C p data for zb-BAs . The observed excellent agreement between the calculated and experimental data indicates the validity of the method used to estimate the thermodynamic properties for the case of boron pnictides. For all three compounds, the heat capacity and entropy of qtz BX phases are slightly higher than those of zb-BX (Fig. ), which is expected for structures containing distorted corner-sharing tetrahedra compared to the ideal zinc-blende structure.