Yan Yun-An, Liu Jian, Shao Jiushu
School of Physics and Optoelectronic Engineering, Ludong University, Shandong 264025, China.
Beijing National Laboratory for Molecules Sciences, Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
J Comput Chem. 2019 Apr 15;40(10):1161-1171. doi: 10.1002/jcc.25751. Epub 2018 Dec 27.
Starting from the position-momentum integral representation, we apply the correction operator method to the derivation of a uniform semiclassical approximation for the quantum propagator and then extend it to approximate the Boltzmann operator. In this approach, the involved classical dynamics is determined by the method itself instead of given beforehand. For the approximate Boltzmann operator, the corresponding classical dynamics is governed by a complex Hamiltonian, which can be described as a pair of real Hamiltonian systems. It is demonstrated that the semiclassical Boltzmann operator is exact for linear systems. A quantum propagator in the complex time is thus proposed and preliminary numerical results show that it is a reasonable approximation for calculating thermal correlation functions of general systems. © 2018 Wiley Periodicals, Inc.
从位置 - 动量积分表示出发，我们将修正算符方法应用于量子传播子的均匀半经典近似的推导，然后将其扩展以近似玻尔兹曼算符。在这种方法中，所涉及的经典动力学由方法本身确定，而不是预先给定。对于近似玻尔兹曼算符，相应的经典动力学由一个复哈密顿量支配，它可以描述为一对实哈密顿系统。结果表明，半经典玻尔兹曼算符对于线性系统是精确的。因此提出了复时间中的量子传播子，初步数值结果表明它是计算一般系统热关联函数的合理近似。© 2018威利期刊公司。
