Phosphorous pentoxide is important as a common component of glass and as a reference material for formation enthalpy and free energy of phosphate minerals. These researchers calculate constant-volume and constant-pressure heat capacities of three polymorphs of solid phosphorous pentoxide at standard conditions and at above-ambient temperature. Heat capacity of the P4O10 molecular liquid phase will also be calculated. Carr-Parrinello molecular dynamics will be used as implemented in Quantum Espresso. Vibrational contributions to heat capacities will be included through the velocity autocorrelation function.