Quantum statistics and classical mechanics: Real time correlation functions from ring polymer molecular dynamics
Quantum statistics and classical mechanics: Real time correlation functions from ring polymer molecular dynamics
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DOI：
10.1063/1.1777575
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发表时间：
2004-08-22
影响因子：
4.4
通讯作者：
Manolopoulos, DE
中科院分区：
文献类型：
--
作者：
Craig, IR;Manolopoulos, DE
我们提出了一种基于路径积分（Parrinello-Rahman）分子动力学的近似方法，用于计算涉及位置相关算子的 Kubo 变换实时相关函数。该方法给出了零时精确的量子力学相关函数，完全满足量子力学详细平衡条件，并且对于形式为 (C) over tilde (Ax)(t) 和 (C) over tilde (xB)(t) 的相关函数，它给出了谐波势的精确结果。正如我们通过一些示例计算所说明的那样，它在短时间内对于更一般的势和相关函数也相当有效。该方法提供了对纯经典分子动力学的一致改进，这在低温条件下最为明显。(C) 2004 美国物理研究所。
We propose an approximate method for calculating Kubo-transformed real-time correlation functions involving position-dependent operators, based on path integral (Parrinello-Rahman) molecular dynamics. The method gives the exact quantum mechanical correlation function at time zero, exactly satisfies the quantum mechanical detailed balance condition, and for correlation functions of the form (C) over tilde (Ax)(t) and (C) over tilde (xB)(t) it gives the exact result for a harmonic potential. It also works reasonably well at short times for more general potentials and correlation functions, as we illustrate with some example calculations. The method provides a consistent improvement over purely classical molecular dynamics that is most apparent in the low-temperature regime.(C) 2004 American Institute of Physics.