Institut für Theoretische Physik und Interdiziplinäres Zentrum für Molekulare Materialien, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen, Germany.
J Chem Phys. 2013 Jul 21;139(3):031102. doi: 10.1063/1.4816124.
A new method based on an extension of ring-polymer molecular dynamics is proposed for the calculation of thermal correlation functions in electronically nonadiabatic systems. The ring-polymer dynamics are performed using a continuous-variable representation of the electronic states within the mapping approach, such that the electronic and nuclear degrees of freedom are treated on an equal footing. Illustrative applications of the method show good agreement with exact quantum results for the dynamics over short to moderate times and reveal a systematic improvement over the classical implementation of the mapping approach (single-bead limit). Being based on trajectories, the method scales well with the number of degrees of freedom and will be applicable to simulate certain nonadiabatic processes in complex molecular systems.
提出了一种基于环聚合物分子动力学扩展的新方法，用于计算非绝热电子系统中的热关联函数。环聚合物动力学是通过映射方法中电子态的连续变量表示来进行的，从而使电子和核自由度得到平等对待。该方法的应用实例表明，在短至中等时间内，该方法与动力学的精确量子结果具有很好的一致性，并显示出相对于映射方法的经典实现（单珠极限）的系统改进。该方法基于轨迹，因此可以很好地扩展自由度的数量，并将适用于模拟复杂分子系统中的某些非绝热过程。
