  Starting from the Hamiltonian for a dimer which includes all the electronic
and electron-phonon terms consistent with a non-degenerate orbital, by a
sequence of displacement and squeezing transformation we obtain an effective
polaronic Hamiltonian. The renormalized electronic interactions differ from the
results of semiclassical or perturbative treatments. The properties of the
variationally determined ground state of two particles in the orbital are
discussed for variable dimer length in the adiabatic limit.
