Price S L, Richards N G
Department of Theoretical Chemistry, University Chemical Laboratory, Cambridge, U.K.
J Comput Aided Mol Des. 1991 Feb;5(1):41-54. doi: 10.1007/BF00173469.
We compare two methods (Mulliken charges and a distributed multipole analysis, DMA) of representing an ab initio charge distribution for calculating the electrostatic field and potential outside the molecule, using pyrimidine and the RNA base uracil as examples. This is done using a 3-D graphical display of the electrostatic fields, which, when used with real-time rotation, zooming and clipping, has many advantages for qualitatively assessing the electrostatic interactions of a molecule. The errors involved in using Mulliken point charges may be of similar magnitude to the total electrostatic field in regions which are important in recognition processes. The DMA representation automatically includes the anisotropic electrostatic effects of non-spherical features in the charge distribution of each atom, and yet the displayed electrostatic fields around the atoms which have lone-pair density do not show marked anisotropy.
我们以嘧啶和RNA碱基尿嘧啶为例，比较了两种用于表示从头算电荷分布以计算分子外部静电场和电势的方法（穆利肯电荷法和分布式多极分析，DMA）。这是通过静电场的三维图形显示来完成的，当与实时旋转、缩放和裁剪一起使用时，它在定性评估分子的静电相互作用方面具有许多优势。在识别过程中重要的区域，使用穆利肯点电荷所涉及的误差可能与总静电场的大小相似。DMA表示自动包含每个原子电荷分布中非球形特征的各向异性静电效应，然而，具有孤对电子密度的原子周围显示的静电场并未表现出明显的各向异性。
