Thermodynamic and electronic properties of alkali-metal atom fluids

By use of a free-energy model, the properties of a fluid composed of neutral atoms and diatomic molecules, positive ions and molecular ions, and an electron Fermi gas are calculated. The interactions include excluded volume, internal molecular binding, electron-neutral s-wave scattering, and screened Hartree interactions. For rubidium and cesium parametrizations, the vapor-liquid phase transitions with their critical points, the insulator-metal transitions, and the isothermal electrical conductivities and magnetic susceptibilities are obtained.