Studies Of Charge Distributions In Amino-acid Dipeptide And Nitrenium Ions Reaction By ABEEM σπ

According to density functional theory, the electron density of a system determines all properties of the system. So accurate calculation of charge distributions in a molecular system plays an important role in explaining and predicting its structure and properties. Conventional ab initio methods are hard to apply to large molecular systems, because it spends much time. Hence, developing an accurate and economic method to probe the properties of large molecules is a promising research area in current theoretical chemistry. We have built and developed an atom-bond electron-egativity equalization σπ model (ABEEMσπ) on the basis of density functional theory and electronegativity equalization principle. Using ABEEM σπ, charge distributions of amino-acid dipeptide and nitrenium ions reaction are calculated. The results of calculation may be well relevant to those of ab initio method. Compared to ab initio method it is timesaving. Especially in the reaction of nitrenium ions, charges which transfer in the reaction is corresponding to the chemical shift. As a result, ABEEMσπ has a widespread prospect in developing and applying to the systems of reaction.