AI 中文总结
介绍两种用耦合高斯波包的非绝热半经典方法，通过强制假设或变分原理推导经典运动方程，经合理性检验后用于两个非绝热势能场景，变分解冻高斯方法更准确，借助经典轨迹再现非绝热分子动力学。
AI 中文摘要
我们介绍了两种非绝热半经典方法，它们采用两个耦合的高斯波包，每个波包在单独的 diabatic 势能面上传播。波包采用解冻高斯形式，由考虑 diabatic 耦合的经典运动方程驱动。一种情况是通过强制解冻高斯假设推导经典运动方程，另一种是对解冻高斯假设应用含时变分原理。在两种近似都能重现拉比振荡的合理性检验后，将方法应用于两个非绝热势能场景。第一个涉及两个耦合的位移谐振子，第二个包括与上解离态耦合的莫尔斯势，模拟光解离过程。在这两种情况下，变分解冻高斯方法相当准确，而标准解冻高斯方法未能完全捕捉非绝热效应。最终，通过两条经典轨迹再现非绝热分子动力学，而不引入任何人为跳跃或其他特殊非经典效应。
英文摘要
We introduce two non-adiabatic semiclassical methods that employ two coupled Gaussian wavepackets, each one traveling on a separate diabatic potential energy surface. The wavepackets take the form of thawed Gaussians and are driven by classical equations of motion which account for the diabatic coupling. The classical equations of motion are derived in one case by enforcing the thawed Gaussian ansatz, while in the other the time-dependent variational principles to the thawed Gaussian ansatz. After a sanity check where both approximations reproduce Rabi oscillations, the methods are applied to two non-adiabatic potential energy scenarios. The first one involves two coupled displaced harmonic oscillators, as in a typical electron transfer reaction. The second one comprises a Morse potential coupled to an upper dissociative state, modeling a photo-dissociation process. In both scenarios, the variational thawed Gaussian approach is quite accurate, while the standard thawed Gaussian one fails to fully capture the non-adiabatic effects. Ultimately, non-adiabatic molecular dynamics is reproduced by means of two classical trajectories without introducing any artificial jump or other ad-hoc non-classical effects.
