Density-functional theory of simple classical fluids. II. Localized excess electron states

Abstract

Localized electron states in the rare-gas fluids are investigated using a density-functional formalism for the interacting fluid and a contact potential for the electron-atom interaction. The results are in qualitative agreement with previous theories which use simpler models of the fluid in that no localized states are found in dilute helium gas, neon gas, argon, krypton, and xenon, while localized states are found in dense helium gas and in liquid neon near the liquid-gas coexistance curve. There are, however, large quantitative differences between the present results and those of the other theories. In particular, it is predicted that the localized states in neon will become unstable at sufficiently large liquid densities which are still below the density at which the liquid-solid transition occurs. The effectiveness of the localized states as a mechanism for vapor nucleation in liquid neon is investigated as is the possibility that the liquid density profile is not monotonic in the vicinity of the localized electron. No oscillatory behavior of the density profile is found.