DERIVATION AND PILOT APPLICATION OF A SCHEME FOR INTERMEDIATE HAMILTONIANS IN FOCK SPACE

A Fock space formulation of the intermediate, Hamiltonian approach is derived by introducing shift operators in the equations determining effective Hamiltonians in Fock space. A non-hermitian intermediate Hamiltonian is constructed from the Fock space Bloch equation. An alternative derivation, based on a similarity transformation expression, is presented providing access to hermitian intermediate Hamiltonians. In a pilot application, the potential curves of the two lowest 1-SIGMA(g)+ states of the H-2 molecule are calculated demonstrating the applicability of the scheme.