Centre of Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø, Tromsø, Norway.
J Phys Chem B. 2011 Mar 31;115(12):3027-37. doi: 10.1021/jp1101913. Epub 2011 Mar 10.
We present the theory and an implementation of the combined quantum mechanics/molecular mechanics/polarizable dielectric continuum (QM/MM/PCM) method. This is a fully polarizable layered model designed for effective inclusion of a medium in a quantum-mechanical calculation. The short-range part of the solvent electrostatic potential is described by an atomistic model while the long-range part of this potential is described by a dielectric continuum. The QM/MM/PCM method has been implemented in combination with QM linear response techniques allowing for the assessment of, e.g., vertical electronic excitation energies and linear dipole-dipole polarizabilities, in all cases using a nonequilibrium formulation of the environmental response. The model is general, but is here implemented for the case of density functional theory. Numerical examples are given for solvatochromic shifts relating to a set of organic molecules in aqueous solution. We find in general the QM/MM/PCM interface to exhibit a faster convergence with respect to the system size as compared to the use of QM/MM only.
我们提出了一种组合量子力学/分子力学/极化介电连续体（QM/MM/PCM）方法的理论和实现。这是一个完全可极化的分层模型，旨在有效地将介质纳入量子力学计算中。溶剂静电势的短程部分由原子模型描述，而该势的长程部分由介电连续体描述。QM/MM/PCM 方法与 QM 线性响应技术相结合，允许评估例如垂直电子激发能和线性偶极子极化率，在所有情况下都使用环境响应的非平衡公式。该模型具有通用性，但在此针对密度泛函理论的情况进行了实现。数值示例给出了与一系列有机分子在水溶液中的溶剂化色移有关的情况。我们发现，与仅使用 QM/MM 相比，QM/MM/PCM 接口通常表现出更快的系统尺寸收敛速度。
