The Calculation Of Charge Distributions In Groups Containing Phosphorus Element

The calculation of charge distributions in groups containingphosphorus elementThe groups containing phosphorus element, especially in the nucleotide, play an important role in vital progress and have been widely used in the fields of organic, biological and medicine. Since group charge distributions are closely related to group properties, it is important to calculate charge distributions of groups containing phosphorus element. Conventional ab initio methods are hard to apply to the large molecular systems, so we should develop an accurate and economic method to probe the relationship between structures and properties of large molecules. We have proposed modified electronegativity equalization method (MEEM) based on density functional theory and electronegativity equalization principle. Using a separated program, through regression and least-squares optimization, the parameters of atoms in groups are determined. By these parameters, the charge distributions and the energies of some groups containing phosphorus element are calculated. The results show well agreement with those obtained by ab initio methods.