  We consider the formation and stability of the vibronic polaron arising in a
degenerate or nearly degenerate electronic system coupled to an appropriate
vibrational mode. We define the electron-phonon coupling as a mixing of the
electronic states by the phonon mode. Our investigation is similar to that
carried out recently by Dennis Clougherty though by introducing a different
coupling operator. This extends the vibronic coupling range beyond the limits
set by the difference in electronic density of the progenitor bands thereby
widening the applicability range of the coupled soliton.
