Tim's paper on modeling absorption spectra by combining the ensemble and Franck-Condon approaches has been published in J. Chem. Phys. and has been chosen as an Editor's Pick!
In this manuscript, we present an approach for modeling the band shapes of electronic absorption spectra of molecules in solution that combines both ensemble sampling of solute-solvent configurations and vibronic effects. For dyes in solution, capturing both inhomogeneous broadening of the solvent environment (which may be non-Gaussian for strong solute-solvent interactions) and the contribution to broadening from vibronic transitions is necessary for obtaining the correct spectral shape. Our approach treats all temperature effects classically through ensemble sampling of the ground state potential energy surface (including anharmonic regions of the PES), whereas the vibronic fine structure resulting from nuclear wave functions is treated at 0K through the Franck-Condon principle. These two approaches are then combined by dressing the vertical excitation energies with the Franck-Condon vibronic shape function.
