We derive the behavior of the Thomas-Fermi equation of state near both the ‘‘hot-curve’’ (the limit as T→∞ for a fixed de Broglie length) and the ‘‘cold-curve’’ (the zero-temperature isotherm) by using perturbation methods. We derive efficient computational formulas for the coefficients in these expansions using Padé methods. We are able to meld all of these results into a structurally correct representation of the Thomas-Fermi fluid pressure. We indicate how this representational structure can be used to construct the equation of state for realistic materials over large ranges of temperature and pressure. We also discuss the computation of the degree of ionization with and without the exchange correction.

• Received 15 February 1991

DOI:https://doi.org/10.1103/PhysRevA.44.2271