Nonadiabatic Field: A Conceptually Novel Approach for Nonadiabatic Quantum Molecular Dynamics

Area of Science:

• Quantum chemistry
• Chemical dynamics
• Computational physics

Background:

• Accurate simulation of quantum dynamics is crucial for understanding complex chemical processes.
• Existing methods like Ehrenfest dynamics and surface hopping have limitations in certain regimes.
• Coupled electron-nuclear motion is fundamental in many chemical reactions and material properties.

Purpose of the Study:

• To introduce and validate the Nonadiabatic Field (NaF) method for quantum dynamics.
• To demonstrate NaF's capability in handling strong electron-nuclear coupling and bifurcating nuclear motion.
• To provide a reliable computational tool for simulating nonadiabatic quantum dynamics in complex systems.

Main Methods:

• Development of the Nonadiabatic Field (NaF) method based on generalized phase space formulation.
• Utilizing constraint phase space (CPS) for electronic degrees of freedom and Wigner phase space for nuclear degrees of freedom.
• Proposing efficient integrators for NaF equations of motion in both adiabatic and diabatic representations.

Main Results:

• NaF accurately describes the interplay between electronic and nuclear motion across various coupling regimes.
• The method shows robustness and is relatively insensitive to the choice of electronic time correlation function representation.
• Validation against numerically exact results for benchmark gas-phase and condensed-phase models.

Conclusions:

• Nonadiabatic Field (NaF) is a conceptually novel and effective approach for quantum dynamics.
• NaF provides a reliable and practical tool for simulating coupled electron-nuclear dynamics in complex systems.
• The method holds significant potential for advancing the understanding and design of chemical processes.