Non-adiabatic direct quantum dynamics using force fields: Toward solvation

• DOI: 10.1063/5.0204911
• Publication Date: 2024-05-07T09:57:31Z
• Authors: L. L. E. Cigrang; J. A. Green; S. Gómez; J. Cerezo; R. Improta; G. Prampolini; F. Santoro; G. A. Worth
• Keywords: Force Field

Quantum dynamics simulations are becoming a powerful tool for understanding photo-excited molecules. Their poor scaling, however, means that it is hard to study molecules with more than few atoms accurately, and major challenge at the moment inclusion of molecular environment. Here, we present proof principle way break two bottlenecks preventing large but accurate simulations. First, problem providing potential energy surfaces general system addressed by parameterizing standard force field reproduce molecule’s excited-states, including all-important vibronic coupling. While not shown here, this would trivially enable use an explicit solvent. Second, help scaling nuclear propagation, hierarchy approximations introduced variational multi-configurational Gaussian method retains quantum wavepacket description key degrees freedom uses classical trajectories remaining in mechanics/molecular mechanics like approach. The referred as (FF-QD), two-state ππ*/nπ* model uracil, excited its lowest bright ππ* state, used test case.