A Geminal Method Based on the Generalized Electron Pairing Applied to the Heisenberg Model of Hydrocarbons

Abstract

In the approximate valence bond (VB) description of molecular electronic structures, the resonating VB effect might be incorporated in an efficient manner by mixing the triplet component into conventional singlet geminals. We developed a variational optimization scheme for this generalized pairing type wave function in the framework of the spin Hamiltonian model. With numerical verifications, we found the resonance stabilization is partially described through the contamination of higher spin states for molecules such as non-Kekulé hydrocarbons.