Self-Consistent Equation of State of Solid Hydrogen

In the calculation of the static and dynamic properties of quantum crystals, the usual substitution of the static interaction potential for the free energy is no longer justified. A self-consistent description of lattice vibrations is therefore necessary. Using the Debye approximation one gets a simple implicit equation for the zero-point vibration. For solid hydrogen this equation is shown to be physically meaningful and, notwithstanding integration difficulties, to be a convenient tool for testing the compatibility of different sets of experimental data and theoretical interaction-energy calculations. Compression data are shown to be compatible with inelastic neutron scattering and calorimetric data, and Trubitsyn's interaction potential is found to agree with the compression data over the entire experimental range.