Vibronic States of a Dimer

Equations representing the vibronic states of an excited dimer are developed, using adiabatic strong‐coupling state vectors; the equations can be uncoupled using an approximation scheme and the problem reduces to solving a one‐dimensional, two‐parameter Schrodinger equation with a complicated potential. It is analyzed qualitatively and analytic solutions are derived for a certain domain in the parameter space. The vibrations are shown to fall into two classes: distorted oscillator functions of a single‐well Hamiltonian, and vibrations belonging to a double‐well potential. Some properties of the double well are investigated and some qualitative conclusions are drawn. The theory is also examined in the weak‐coupling limit and shown to yield the correct answer.