Application of time-independent cumulant expansion to calculation of Franck-Condon profiles for large molecular systems.

In this contribution, advantages and disadvantages of the time-independent and time-dependent approaches for Franck-Condon profile calculations are discussed within the displaced-distorted-rotated harmonic oscillator approximation. Particular strengths and prospects of a previously developed time-independent cumulant expansion in the calculation of a Franck-Condon profile for UV/Vis absorption spectra are demonstrated for the specific case of the S0(1Ag) --> S1(1B3u) transition of terrylene at various temperatures.