A localized spin-orbital theory of chemisorption

A many-electron theory of chemisorption is described and illustrated by a model calculation, for a hydrogen atom bonded to a lithium metal surface. A basis of atomic spin—orbitals is used to describe the many-electron states of this system, as is done in valence bond calculations for molecules. These spin—orbitals are assigned either to a region X near the adsorbate, where the electron distribution has been altered by the chemisorption, or to a region Q outside X in which the electron distribution is that of the clean metal. The calculation yields the variation in binding energy with adsorbate—substrate separation and details of the electron distribution in X.