Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
J Chem Phys. 2013 Sep 28;139(12):124102. doi: 10.1063/1.4821590.
We introduce mapping-variable ring polymer molecular dynamics (MV-RPMD), a model dynamics for the direct simulation of multi-electron processes. An extension of the RPMD idea, this method is based on an exact, imaginary time path-integral representation of the quantum Boltzmann operator using continuous Cartesian variables for both electronic states and nuclear degrees of freedom. We demonstrate the accuracy of the MV-RPMD approach in calculations of real-time, thermal correlation functions for a range of two-state single-mode model systems with different coupling strengths and asymmetries. Further, we show that the ensemble of classical trajectories employed in these simulations preserves the Boltzmann distribution and provides a direct probe into real-time coupling between electronic state transitions and nuclear dynamics.
我们介绍了映射变量环聚合物分子动力学（MV-RPMD），这是一种用于直接模拟多电子过程的模型动力学。该方法是 RPMD 思想的扩展，它基于使用连续笛卡尔变量表示量子玻尔兹曼算符的精确、虚时间路径积分表示，这些变量既适用于电子态，也适用于核自由度。我们通过对一系列具有不同耦合强度和不对称性的两态单模模型系统的实时热相关函数的计算，证明了 MV-RPMD 方法的准确性。此外，我们还表明，这些模拟中使用的经典轨迹集合保持了玻尔兹曼分布，并提供了对电子态跃迁和核动力学之间实时耦合的直接探测。
