A simple but accurate ‘‘core-tail’’ pseudopotential approach to the calculation of the conduction-band energy V0 of quasifree excess electrons and positrons in nonpolar fluids

Abstract

The conduction-band minimum energy V0 (relative to vacuum) of quasifree excess electrons and positrons in fluid rare gases, methane, and silane is calculated as a function of fluid density n. The calculations are performed within the framework of the Wigner–Seitz mean-field approximation for nonpolar fluids, using a simple ‘‘core-tail’’ pseudopotential to model the excess electron (positron)–atom/molecule interactions. This pseudopotential is determined only by the atomic/molecular polarizability and the electron (positron) scattering length. Despite the simplicity of our approach, the present V0(n) results, which contain no adjustable parameters, show close agreement with those obtained using more elaborate potentials and with available experimental data.