Hu Hao, Lu Zhenyu, Yang Weitao
Department of Chemistry, Duke University, Durham, North Carolina 27709.
J Chem Theory Comput. 2007 May;3(3):1004-13. doi: 10.1021/ct600295n.
We develop here a new method to fit the molecular electrostatic potentials obtained in quantum mechanical calculations to a set of classical electrostatic multipoles, usually point charges located at atomic positions. We define an object function of fitting as an integration of the difference of electrostatic potentials in the entire 3-dimensional physical space. The object function is thus rotationally invariant with respect to the molecular orientation and varies smoothly with respect to molecular geometric fluctuations. Compared with commonly employed methods such as the Merz-Singh-Kollman and CHELPG schemes, this new method, while possessing comparable accuracy, shows greatly improved numerical stability with respect to the molecular positions and geometries. The method can be used in the fitting of electrostatic potentials for the molecular mechanics force fields and also can be applied to the calculation of electrostatic polarizabilites of molecular or atomic systems.
我们在此开发了一种新方法，用于将量子力学计算中获得的分子静电势拟合为一组经典静电多极子，通常是位于原子位置的点电荷。我们将拟合的目标函数定义为整个三维物理空间中静电势差的积分。因此，目标函数相对于分子取向是旋转不变的，并且相对于分子几何波动平滑变化。与常用方法如Merz-Singh-Kollman和CHELPG方案相比，这种新方法虽然具有相当的精度，但在分子位置和几何形状方面显示出大大提高的数值稳定性。该方法可用于分子力学力场的静电势拟合，也可应用于分子或原子系统的静电极化率计算。
