Condensed phase molecular dynamics using interpolated potential energy surfaces with application to the resolvation process of coumarin 153

Abstract

Interpolated potential energy surfaces (PESs) have been used for performing reliable molecular dynamics (MD) simulations of small molecular reactions. In this article, we extend this method to MD simulations in condensed phase and show that the same scheme can also be feasibly used when it is supplemented with additional terms for describing intermolecular interactions. We then apply the approach for studying the resolvation process of coumarin 153 in a number of polar solvents. We find that the interpolated surface actually reproduces experimentally found features much better than the conventional force field based potential especially in terms of both dynamics Stokes shift in the short time limit and solute vibrational decoherence. This shows that the solute vibrational effect is important to some degree along the resolvation and should be modeled properly for accurate description of the related dynamics. The stability issue of trajectories on the interpolated PESs is also discussed, in regard to the goal of reliably performing long time simulations. Operational limitations of the present scheme are also discussed. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3605302]