First-principles thermochemical properties of hexagonal and cubic phase BaMnO3

BaMnO3 perovskite oxide is an interesting material for many high-temperature technological applications due to its facile reduction capacity at reasonably low temperature. The thermochemical properties of BaMnO3 largely determine this reduction behaviour at high temperature. However, the temperature-dependent thermochemical properties of hexagonal and cubic BaMnO3 remain uncharacterized. Herein the structural and thermochemical properties (entropy, specific heat and relative molar enthalpy) of hexagonal and cubic BaMnO3 perovskites are predicted using first principles calculations. Their corresponding phonon dispersions and vibrational density of states are illustrated to show the individual atomic contributions to their thermochemical properties. It is demonstrated that the choice of generalized gradient approximation DFT functional does not appreciably influence the structural or thermochemical properties. Data Availability: The raw data required to reproduce these findings are available from the authors upon reasonable request.