TIME-DEPENDENT THEORETICAL TREATMENT OF INTERVALENCE ABSORPTION-SPECTRA - EXACT CALCULATIONS IN A ONE-DIMENSIONAL MODEL

Intervalence absorption spectra are calculated and interpreted by usin g the time-dependent theory of spectroscopy and the Feit and Fleck met hod of numerically integrating the time-dependent Schrodinger equation . These methods give exact eigenvalues and eigenfunctions (within the constraints of the model and the numerical accuracy of the computer im plementation). The results provide a new physical picture of the absor ption spectrum and emphasize that Born-Oppenheimer separation of elect ronic and vibrational wave functions does not apply to the problem. Th e details of the calculation are discussed and interpreted. The exact calculation is compared to results obtained in the adiabatic limit. Th e effect of the temperature on intervalence absorption spectra is disc ussed. Localization and delocalization are interpreted in terms of the eigenfunctions.