电负性均衡

电负性是分子中一个原子把电子拉向它自身的能力,是化学理论的基本概念之一。继Pauling建立第一个电负性标度后,提出了众多的电负性标度。只是在密度泛函理论的基础上,电负性概念和电负性均衡原理,才被精密地论证。近二十多年来,电负性理论的重要发展是:应用电负性均衡模型或方法,可以快速地计算分子体系的电荷分布,从而确定分子的其他性质,甚至包括分子的结构和反应性指标。通常的电负性均衡方法只把分子划分到原子区域,虽然简单直观,但其精度和应用范围受到限制。原子与键电负性均衡方法,把分子划分到包括原子区域、化学键区域和孤对电子区域,能够较快速精密地计算分子的电荷分布和其他性质,并被应用到构建新一代可极化或浮动电荷力场的探索中,有广阔的应用前景。

Electronegativity Equalization

Electronegativity is the power of an atom attracting electron to itself in a molecule.It is a basic concept in chemistry.Pauling proposed the first electronegativity scale and after then many electronegativity scales were proposed.It is only on the basis of density functional theory that the concept and electronegativity principle were precisely proved theoretically.In recent decades,there have been some important developments of the electronegativity theory.Applying the electronegativity equalization model or method,one can rapidly calculate the charge distribution of a large molecule and then calculate the related properties,even molecular structure and reactivity indexes.The usual electronegativity equalization method divides a molecule only to atomic regions its accuracy and application are limited although it is simple and intuitive.Atom-bond electronegativity equalization method divides a molecule into not only atomic regions but also bond and lone-pair regions so that it can rapidly and accurately calculate molecular charge distribution and other properties,and recently it is also applied to develop a new generation of polarizable force field.