A phase-space semiclassical approach for modeling nonadiabatic nuclear dynamics with electronic spin

Area of Science:

• Quantum dynamics
• Chemical physics
• Computational chemistry

Background:

• Nonadiabatic dynamics are crucial for chemical relaxation, photochemistry, and electron transfer.
• Existing quasiclassical methods struggle with electronic systems possessing spin degrees of freedom.

Purpose of the Study:

• To develop a practical quasiclassical method for simulating nonadiabatic dynamics in systems with spin.
• To extend Tully's surface hopping approach to phase space for handling complex Hamiltonians.

Main Methods:

• Generalizing Tully's surface hopping dynamics from coordinate space to phase space.
• Isolating diabats, applying phase gauge transformations, and diagonalizing the Hamiltonian in phase space.
• Developing an algorithm valid in both adiabatic and nonadiabatic limits, including Berry curvature effects.

Main Results:

• A novel semiclassical algorithm for nonadiabatic dynamics in the presence of spin-orbit coupling and/or external magnetic fields.
• The method is applicable to two-electronic state systems with complex-valued Hamiltonians lacking time-reversal symmetry.
• The algorithm successfully incorporates Berry curvature effects.

Conclusions:

• The new phase-space surface hopping method provides a practical tool for studying complex spin-coupled nuclear-electronic-spin systems.
• This advancement is expected to facilitate simulations of cutting-edge experiments, such as those exhibiting chiral-induced spin selectivity.