A self-consistent theory of inhomogeneous liquid metals: Calculations of the electron and ion density profiles and the liquid-vapour surface tension of the alkali metals

Assuming that the electron-ion pseudopotential is weak the authors have developed a density functional theory for the one-particle densities and the thermodynamic properties of inhomogeneous liquid simple metals. They show that the Helmholtz free energy can be written as the sum of the total electrostatic energy, the non-Coulombic part of the free energy of an inhomogeneous electron jellium G _e(n), the corresponding quantity for an inhomogeneous one-component classical plasma G _i( rho ) and a pseudopotential coupling term. In the limit of a uniform liquid their theory yields electron-electron, ion-ion and electron-ion direct correlation functions that are identical to those proposed recently by Postogna and Tosi (1980) for a weakly coupled electron-ion plasma.