Heindel Joseph P, Sami Selim, Head-Gordon Teresa
Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California 94720, United States.
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
J Chem Theory Comput. 2024 Oct 8;20(19):8594-8608. doi: 10.1021/acs.jctc.4c00812. Epub 2024 Sep 17.
We introduce a general framework for many-body force fields, the Completely Multipolar Model (CMM), that utilizes multipolar electrical moments modulated by exponential decay of electron density as a common functional form for all terms of an energy decomposition analysis of intermolecular interactions. With this common functional form, the CMM model establishes well-formulated damped tensors that reach the correct asymptotes at both long- and short-range while formally ensuring no short-range catastrophes. CMM describes the separable EDA terms of dispersion, exchange polarization, and Pauli repulsion with short-ranged anisotropy, polarization as intramolecular charge fluctuations and induced dipoles, while charge transfer describes explicit movement of charge between molecules, and naturally describes many-body charge transfer by coupling into the polarization equations. We also utilize a new one-body potential that accounts for intramolecular polarization by including an electric field-dependent correction to the Morse potential to ensure that CMM reproduces all physically relevant monomer properties including the dipole moment, molecular polarizability, and dipole and polarizability derivatives. The quality of CMM is illustrated through agreement of individual terms of the EDA and excellent extrapolation to energies and geometries of an extensive validation set of water cluster data.
我们引入了一种用于多体势场的通用框架——完全多极模型（CMM），该模型利用由电子密度指数衰减调制的多极电矩，作为分子间相互作用能量分解分析所有项的通用函数形式。通过这种通用函数形式，CMM模型建立了公式良好的阻尼张量，该张量在长程和短程都能达到正确的渐近线，同时在形式上确保不存在短程灾难。CMM用具有短程各向异性的色散、交换极化和泡利排斥的可分离EDA项来描述，将极化描述为分子内电荷涨落和诱导偶极，而电荷转移描述分子间电荷的明确移动，并通过耦合到极化方程自然地描述多体电荷转移。我们还利用一种新的单体势，通过对莫尔斯势包含电场相关修正来考虑分子内极化，以确保CMM能再现所有物理相关的单体性质，包括偶极矩、分子极化率以及偶极和极化率导数。通过EDA各项的一致性以及对大量水团簇数据验证集的能量和几何结构的出色外推，展示了CMM的质量。
