MODEL CALCULATION OF THE INTERACTION TERMS AND GROUND-STATES OF THE EXTENDED HUBBARD-MODEL ON A DIMER

We consider the complete extended Hubbard Hamiltonian on a dimer, incl uding all one- and two-body terms. The energy eigenvalues and eigenvec tors and various correlation functions have been obtained in explicit form. Introducing model Wannier orbitals we have evaluated the interac tion parameters as functions of the dimer length and orbital shape. Mi nimization of the lowest-energy eigenvalue yields the equilibrium shap e for different fillings.