解析能量梯度在组合二级 Møller-Plesset 微扰理论和极化力场计算中的应用。

Analytic energy gradient in combined second-order Møller-Plesset perturbation theory and polarizable force field calculation.

机构信息

Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.

出版信息

J Phys Chem A. 2011 Oct 27;115(42):11824-31. doi: 10.1021/jp206425z. Epub 2011 Sep 28.

DOI:10.1021/jp206425z

PMID:21905697

Abstract

Second-order Møller-Plesset perturbation theory (MP2) is used to describe electronic correlation on the basis of Hartree-Fock (HF) variational calculations that incorporate induced dipole polarizable force fields (i.e., QM/MMpol style HF and MP2). The Z-vector equations for regular closed shell and open shell MP2 methods (RMP2, ZAPT2, and UMP2) are extended to include induced dipole contributions to determine the MP2 response density so that nuclear gradient and other properties can be efficiently evaluated. A better estimation of the induced dipole polarization energy can be obtained using the MP2 relaxed density. QM/MMpol style MP2 molecular dynamics simulations are performed for the ground state and first triplet state of acetone solvated by 1024 polarizable water molecules. A switching function is used to ensure energy conservation in QM/MM simulation under periodic boundary condition.

摘要

二阶微扰理论（MP2）是在包含诱导偶极极化力场（即 QM/MMpol 风格 HF 和 MP2）的 HF 变分计算的基础上，用于描述电子相关。将正则闭壳层和开壳层 MP2 方法（RMP2、ZAPT2 和 UMP2）的 Z-向量方程扩展到包括诱导偶极贡献，以确定 MP2 响应密度，从而可以有效地评估核梯度和其他性质。使用 MP2 弛豫密度可以更好地估计诱导偶极极化能。对由 1024 个极化水分子溶剂化的丙酮的基态和第一三重态进行了 QM/MMpol 风格的 MP2 分子动力学模拟。使用切换函数确保在周期性边界条件下 QM/MM 模拟中的能量守恒。