EXTRACTION OF EIGENSTATES FROM AN OPTICALLY PREPARED STATE BY A TIME-DEPENDENT QUANTUM-MECHANICAL METHOD - TOWARD SIMULATION OF INTERMEDIATE CASE RADIATIONLESS TRANSITIONS

We provide a method to simulate ''intermediate case'' radiationless transitions for given potentials. The main step is to extract eigenfunctions from an optically prepared state at a time just after the pump pulse has decayed. We generate Lanczos vectors, from the prepared state, with an energy-filtered Hamiltonian and diagonalize the unfiltered Hamiltonian. Preliminary calculations are performed. For a system of two vibrational degrees of freedom, an accuracy of 10(-5) cm-1 can easily be obtained: the long time dynamics up to almost-equal-to 1 mus is within reach.