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Published on: November 12, 2016
Analytic Nonadiabatic Derivative Couplings Using Noncollinear Spin-Flip TDDFT.
Yu Jing1, Wenxian Qin1, Cheng Fan1
1New Cornerstone Science Laboratory, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Journal of Chemical Theory and Computation
|June 11, 2026
Summary
This study introduces analytic nonadiabatic derivative couplings (NADCs) within a noncollinear spin-flip time-dependent density functional theory (SF-TDDFT) framework, enabling efficient molecular dynamics simulations for photochemical processes.
Area of Science:
- Computational Chemistry
- Theoretical Chemistry
- Quantum Chemistry
Background:
- Nonadiabatic molecular dynamics is crucial for studying photochemical reactions.
- Accurately calculating energies, forces, and nonadiabatic derivative couplings (NADCs) for multiple potential-energy surfaces is a key challenge.
Purpose of the Study:
- To formulate and implement analytic NADCs within the noncollinear spin-flip time-dependent density functional theory (SF-TDDFT) framework.
- To assess the accuracy and stability of the developed analytic NADCs.
- To demonstrate the applicability of the method for nonadiabatic molecular dynamics simulations.
Main Methods:
- Development of analytic NADCs based on the multicollinear noncollinear SF-TDDFT approach.
- Accuracy validation through finite-difference comparisons and Berry phase analysis near conical intersections.
- Application to nonadiabatic molecular dynamics simulations of azomethane and ethylene.
Main Results:
- Analytic NADCs were successfully formulated within the noncollinear SF-TDDFT framework.
- The accuracy of the analytic NADCs was confirmed by comparison with finite-difference results and Berry phase analysis.
- Simulations showed stable and reasonable behavior of the analytic derivative couplings for azomethane and ethylene.
Conclusions:
- The developed analytic NADCs are accurate and stable for nonadiabatic molecular dynamics.
- The computational cost is comparable to existing SF-TDDFT methods, making it suitable for moderately large systems.
- This advancement facilitates more efficient and accurate investigations of photochemical reaction mechanisms.
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