Abstract

We present the high-temperature thermodynamic properties of graphite from anharmonic first-principles theory. The ab initio electronic structure results from density functional theory combined with lattice dynamics methods used to model anharmonic lattice vibrations. This combined approach produces graphite free energies and specific heats that compare well with results from available experiments and models empirically representing experimental data such as: B.CALPHAD. We show that the anharmonic theory of phonons is essential for accurate thermodynamic quantities above about 1000K.