AI 中文总结
研究统一推广非绝热分子动力学的解冻高斯艾仑费斯特动力学（TGED），通过变分原理推导其全变分形式，给出多种方法成员，分析极限情况，还给出显式几何积分器及近似精确条件。
AI 中文摘要
艾仑费斯特动力学是一种广泛用于非绝热分子动力学的混合量子-经典方法，而解冻高斯波包动力学为绝热核量子动力学提供了一种有效的半经典描述。本文描述了解冻高斯艾仑费斯特动力学（TGED），它统一并推广了这两种方法，能在单一框架内捕捉电子非绝热性和核量子效应。通过将含时变分原理应用于电子和高斯核波包的哈特里积，推导出TGED的全变分形式。用替代的有效局部二次势取代变分处理得到的有效局部二次分子势，产生了无穷多的TGED方法，本文给出了几个成员。分析了一般形式的极限情况，特别表明在核的经典极限下它简化为传统艾仑费斯特动力学，在没有电子耦合时简化为解冻高斯波包动力学。最后，给出了整个方法族的显式几何积分器，并确定了不同近似变得精确的条件。
英文摘要
Ehrenfest dynamics is a widely used mixed quantum--classical approach for nonadiabatic molecular dynamics, whereas thawed Gaussian wavepacket dynamics provides an efficient semiclassical description of adiabatic nuclear quantum dynamics. Here we describe thawed Gaussian Ehrenfest dynamics (TGED), which unifies and generalizes these two methods to capture both electronic nonadiabaticity and nuclear quantum effects within a single framework. The fully variational formulation of TGED is derived by applying the time-dependent variational principle to a Hartree product of electronic and Gaussian nuclear wavepackets. Replacing the effective locally quadratic molecular potential obtained from this variational treatment by alternative effective locally quadratic potentials yields an infinite family of TGED methods, of which we present several members. We analyze the limiting cases of the general formalism and show, in particular, that it reduces to conventional Ehrenfest dynamics in the classical limit for the nuclei and to thawed Gaussian wavepacket dynamics in the absence of electronic coupling. Finally, we present explicit geometric integrators for the entire family of methods and identify the conditions under which the different approximations become exact.
CommentsVarious minor revisions, added Fig. 3, compiled as a reprint
