Comparison between the methods of Glauber states and Lanczos applied to the Jahn-Teller effect in ZnSe:Fe²⁺

Vibronic levels in the strong-coupling limit are not easy to obtain since vibrational and electronic components are extremely mixed. Usual methods based on extrapolations from the adiabatic limit fail. In the present paper we want to compare the Lanczos method and the Glauber states method applied to a case were the strong-coupling limit is approached. The application considers parameters valid suited to the system ZnSe:Fe² for a more realistic interpretation. Stability of the solutions is found and discussed. Advantages and disadvantages of both methods are also discussed.