Determining polarizable force fields with electrostatic potentials from quantum mechanical linear response theory.
Determining polarizable force fields with electrostatic potentials from quantum mechanical linear response theory.
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DOI：
10.1063/1.4953558
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发表时间：
2016-06
期刊：
影响因子：
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通讯作者：
Hao Wang;Weitao Yang
中科院分区：
文献类型：
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作者：
Hao Wang;Weitao Yang
提出了一种新的计算原子极化率的方法，该方法通过拟合线性响应理论中量子力学计算得到的静电势来计算原子极化率。这与基于电子密度的静电势拟合原子电荷的常规方法平行。我们的ESP拟合相结合的诱导偶极子模型的扰动下的所有方向的均匀外电场。外部电场的线性响应的QM计算被用作输入，与感应偶极子模型完全一致，该模型本身是线性响应模型。均匀外电场的方向在所有方向上被积分。方向和QM线性响应计算的集成使得拟合结果与所施加的均匀外部电场的方向和幅度无关。我们的方法的另一个优点是，QM计算只需要一次，在传统的方法，其中许多QM计算需要许多不同的应用电场。从我们的方法得到的分子极化率显示出可比的准确性与那些直接拟合到实验或理论分子极化率。由于ESP是直接拟合的，从我们的方法获得的原子极化率预计将更好地再现静电相互作用。我们的方法被用来计算可转移的原子极化率的极化分子力学的力场和不可转移的分子特定的原子极化率。
We developed a new method to calculate the atomic polarizabilities by fitting to the electrostatic potentials (ESPs) obtained from quantum mechanical (QM) calculations within the linear response theory. This parallels the conventional approach of fitting atomic charges based on electrostatic potentials from the electron density. Our ESP fitting is combined with the induced dipole model under the perturbation of uniform external electric fields of all orientations. QM calculations for the linear response to the external electric fields are used as input, fully consistent with the induced dipole model, which itself is a linear response model. The orientation of the uniform external electric fields is integrated in all directions. The integration of orientation and QM linear response calculations together makes the fitting results independent of the orientations and magnitudes of the uniform external electric fields applied. Another advantage of our method is that QM calculation is only needed once, in contrast to the conventional approach, where many QM calculations are needed for many different applied electric fields. The molecular polarizabilities obtained from our method show comparable accuracy with those from fitting directly to the experimental or theoretical molecular polarizabilities. Since ESP is directly fitted, atomic polarizabilities obtained from our method are expected to reproduce the electrostatic interactions better. Our method was used to calculate both transferable atomic polarizabilities for polarizable molecular mechanics' force fields and nontransferable molecule-specific atomic polarizabilities.