Diagonal Born-Oppenheimer corrections in condensed-phase ring polymer surface hopping

Area of Science:

• Computational Chemistry and Physics
• Quantum Dynamics Simulations

Background:

• Nuclear quantum effects are crucial for accurate nonadiabatic dynamics simulations.
• Ring polymer surface hopping (RPSH) is a mixed quantum-classical method that incorporates these effects using a ring polymer model.
• Variants like centroid (RPSH-CA) and bead (RPSH-BA) approximations exist, along with diagonal Born-Oppenheimer correction (DBOC).

Purpose of the Study:

• To systematically investigate the performance of RPSH-CA and RPSH-BA methods.
• To evaluate the impact of DBOC on RPSH accuracy across various conditions.
• To provide guidance on the applicability of RPSH variants in condensed-phase simulations.

Main Methods:

• Simulations of the spin-boson system using RPSH-CA and RPSH-BA.
• Systematic variation of reaction regimes, reorganization energies, and temperatures.
• Inclusion and assessment of the diagonal Born-Oppenheimer correction (DBOC).

Main Results:

• RPSH-CA demonstrates satisfactory accuracy and robustness for symmetric potentials across regimes.
• DBOC moderately improves RPSH-CA accuracy in intermediate/nonadiabatic regimes at low temperatures.
• RPSH-CA struggles with asymmetric potentials at low temperatures; RPSH-BA is generally unreliable except in high-temperature adiabatic regimes.

Conclusions:

• RPSH-CA is a reliable method for simulating nonadiabatic dynamics, especially with DBOC for specific regimes.
• The effectiveness of DBOC is moderate in RPSH-CA, unlike its detrimental effect in other methods.
• Findings clarify the utility of geometric corrections in RPSH, aiding condensed-phase simulation choices.