Effect of Chromophore Potential Model on the Description of Exciton-Phonon Interactions.
System-bath interactions in nonadiabatic simulations are often depicted by first performing molecular dynamics calculations and then by evaluating excitation energies at the trajectory snapshots. Usually, molecular mechanics models and quantum chemical calculations are used in a mixed manner toward a trade-off between efficiency and accuracy. Here we investigate how this mixing scheme affects that depiction by using various potential energy surfaces (PESs) of coumarin-153 chromophore, with the help of interpolated PESs that can closely match the accuracies of quantum chemical calculations. We find that although spectral densities are computed only with second stage data the PES characteristics during the first sampling stage can still prevail in the densities, with limited influences on related reorganization energies. Our results suggest that using the mixed scheme can be acceptable when dynamics is mainly governed by the integrated effect of all phonon modes, but care must be taken for understanding detailed effects from individual modes.
Center for Self-Assembly and Complexity, Institute for Basic Science (IBS), Pohang 790-784, Korea.|Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.
Chang Woo
CW
Kim
Center for Self-Assembly and Complexity, Institute for Basic Science (IBS), Pohang 790-784, Korea.|Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.
Jae Woo
JW
Park
Center for Self-Assembly and Complexity, Institute for Basic Science (IBS), Pohang 790-784, Korea.|Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.
Young Min
YM
Rhee
environmental effects; exciton phonon coupling; molecular dynamics; spectral density