Dressed-atom approach to embedding and physisorption in metals

A number of solid-state situations exhibit mainly atomic characteristics. Accordingly, for phenomena involving metals, we have developed a ‘‘dressed-atom’’ approach which is implemented computationally via a coupled Hartree-Fock procedure, and which incorporates the surrounding metallic character self-consistently into the dressed-ground-state or excited-atomic-state wave function. The systems which are studied here are He/Na(001), He/Al(001), and Ar/Na(001). The correlation-energy contribution to the self-consistent metal-adatom interaction is considered in the image-potential approximation. It is found that (i) argon binds on Na(001) with an energy of about 60 meV, and (ii) it is more likely for Ar/Na(001) to exhibit its ionic rather than its neutral configuration during excitation from the ground ${}_{}{}^1{}_{}{}^{}\mathrm{S}$ state.