  The coupling between doubly degenerate electronic states and doubly
degenerate vibrations is analysed for an octahedral system on the basis of the
introduction of an anharmonic Morse potential for the vibronic part. The
vibrations are described by anharmonic coherent states and their linear
coupling with the electronic states is considered. The matrix elements of the
vibronic interaction are builded and the energy levels corresponding to the
interaction Hamiltonian are derived.
