The concept of electronegativity (EN) proposed by Pauling describes the power of an atom attracting electrons, and is widely used in discussing various properties of a molecule. However, its precise definition is only recently stated by Parr in terms of the density functional theory (DFT), which develops its study and application in many areas. In this decade, by use of the Sanderson’s electronegativity equalization principle (EEP), the direct calculation of atomic charges in a molecule is of great interest. There is a close relationship between the atomic charge distribution in a molecule and the molecular EN which are two important indices in chemistry. The former denotes the local property and the latter denotes the global property in a molecule. Since ab initio or various semi-empirical molecular orbital methods cannot car The concept of electronegativity (EN) proposed by Pauling describes the power of an atom attracting electrons, and widely used in discussing various properties of a molecule. However, its precise definition is only recently stated by Parr in terms of the density functional theory ( DFT), which develops its study and application in many areas. In this decade, by use of the Sanderson’s electronegativity equalization principle (EEP), the direct calculation of atomic charges in a molecule is of great interest. There is a close relationship between the The former says the local property and the latter said the global property in a molecule. Since ab initio or various semi-empirical molecular orbital methods can not car