Ring Polymer Molecular Dynamics with Electronic Transitions.

Area of Science:

• Quantum chemistry
• Molecular dynamics
• Computational physics

Background:

• Accurate simulation of quantum dynamics is crucial for understanding molecular and material behavior.
• Simultaneously modeling electron and nuclear quantum motion presents significant computational challenges.

Purpose of the Study:

• To develop a novel computational scheme for nonadiabatic simulations of coupled electron-nuclear quantum dynamics.
• To enable accurate real-time simulations of systems with electronic transitions.

Main Methods:

• A new scheme based on the Ehrenfest theorem and ring polymer molecular dynamics.
• Utilizing an isomorphic ring polymer Hamiltonian to solve time-dependent multistate electronic Schrödinger equations self-consistently.
• Employing an independent-bead approach where each bead represents a distinct electronic configuration.

Main Results:

• The method accurately describes real-time electronic population and quantum nuclear trajectories.
• The simulation results show good agreement with exact quantum solutions.
• Successful application to simulate photoinduced proton transfer in H_{2}O-H_{2}O^{+}, matching experimental data.

Conclusions:

• The developed scheme provides a faithful description of coupled electron-nuclear quantum dynamics.
• This approach offers a computationally efficient and accurate tool for studying complex quantum phenomena.
• The method's validity is confirmed by its agreement with both theoretical benchmarks and experimental observations.