Fletcher Theo, Zhu Andrew, Lawrence Joseph E, Manolopoulos David E
Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom.
Laboratory of Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland.
J Chem Phys. 2021 Dec 21;155(23):231101. doi: 10.1063/5.0076704.
We describe a fast implementation of the quasi-centroid molecular dynamics (QCMD) method in which the quasi-centroid potential of mean force is approximated as a separable correction to the classical interaction potential. This correction is obtained by first calculating quasi-centroid radial and angular distribution functions in a short path integral molecular dynamics simulation and then using iterative Boltzmann inversion to obtain an effective classical potential that reproduces these distribution functions in a classical NVT simulation. We illustrate this approach with example applications to the vibrational spectra of gas phase molecules, obtaining excellent agreement with QCMD reference calculations for water and ammonia and good agreement with the quantum mechanical vibrational spectrum of methane.
我们描述了准质心分子动力学（QCMD）方法的一种快速实现，其中平均力的准质心势被近似为对经典相互作用势的一种可分离修正。这种修正是通过在短路径积分分子动力学模拟中首先计算准质心径向和角分布函数，然后使用迭代玻尔兹曼反演来获得一个有效的经典势，该势在经典NVT模拟中再现这些分布函数而得到的。我们通过对气相分子振动光谱的示例应用来说明这种方法，对于水和氨，与QCMD参考计算结果取得了极好的一致性，对于甲烷，与量子力学振动光谱取得了良好的一致性。
