MODEL CALCULATION OF ELECTRON–PHONON COUPLINGS IN A DIMER WITH A NON-DEGENERATE ORBITAL

Abstract

We evaluate all the electron–phonon couplings derived from the one-body and two-body electronic interactions, in both the adiabatic and extreme non-diabatic limit, for a dimer with a non-degenerate orbital built from atomic wave functions of Gaussian shape. We find largely different values of the coupling parameters in the two limits, as well as different expressions of the corresponding terms in the Hamiltonian. Depending on the distance between the dimer ions, some of the two-body couplings are comparable, or even larger than the one-body ones.