| Quantum Monte Carlo techniques; in their various incarnations, calculate ground state or finite temperature properties of many-body quantum systems. We apply the path-integral Monte Carlo method to hydrogen at densities and temperatures in the regime of cooperative thermal and pressure dissociation, relevant to structural models of the giant planets' interiors. We treat the protons and electrons as quantum particles, thereby avoiding the Born-Oppenheimer approximation. Fermi-Dirac exchange statistics are treated within the fixed-node approximation, with the nodes specified by the free Fermi gas. In the region of molecular dissociation, we observe properties consistent with and suggestive of a first order phase transition with positive density discontinuity... |
