An efficient decoherence scheme for fewest switches surface hopping method.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Theoretical Chemistry

Background:

• The fewest switches surface hopping (FSSH) method is prone to over-coherence.
• Developing accurate and efficient decoherence schemes for FSSH is crucial for simulating quantum dynamics.

Purpose of the Study:

• To propose an efficient and accurate decoherence scheme for the augmented FSSH (A-FSSH) method.
• To compare the proposed scheme with existing methods, specifically the parameter-free scheme by Wang and co-workers.

Main Methods:

• Modification of the augmented fewest switches surface hopping (A-FSSH) scheme.
• Implementation and testing of a novel decoherence scheme.
• Comparative analysis against the A-FSSH method and Wang's decoherence scheme.

Main Results:

• The proposed decoherence scheme achieves accuracy comparable to the original A-FSSH method.
• The new scheme demonstrates at least 30 times greater efficiency than the original A-FSSH.
• Wang's scheme is more efficient but lacks accuracy with large diabatic coupling.

Conclusions:

• The modified A-FSSH scheme provides an accurate and significantly more efficient approach to quantum dynamics simulations.
• This work offers a valuable solution for overcoming the over-coherence issue in FSSH simulations.