Generalization of atomshyphen;inhyphen;molecules theory to include independent scaling of inner and outer shells

摘要

Scaled atomshyphen;inhyphen;molecules (SAIM) theory is required for obtaining diatomic fragment eigenvectors, and often useful for providing diatomic fragment potential energy curves, needed as input in the scaled diatomichyphen;inhyphen;molecules (SDIM) method. Independent scaling of inner shells and valence shells is not admitted in the current formulation of SAIM. A new extension is developed here in which atomic eigenfunctions are partitioned into innerhyphen;shell and outerhyphen;shell components. These component functions are rigorously defined as solutions of two simultaneous eigenvalue equations; the Hamiltonians in these equations add to yield the original total atomic Hamiltonian. The component Hamiltonians so defined are shown to contain potential energy functions which are approximately homogeneous functions of degree minus one; hence, Coulombhyphen;like. Thus, the innerhyphen;shell and outerhyphen;shell eigenfunctions may be scaled independently using methods generalized from standard scaled atomshyphen;inhyphen;molecules (SAIM) theory. Preliminary applications to LiH, BeH, and Li2, and their positive ions, yield dissociation energies accurate to 7 kcal/mol or better.