Calculating The Molecular Electrostatic Potential By ABEEM σπ Model

Many physical and chemical properties of molecule are closely related to its electrostatic potential. Molecular electrostatic potential, a theory character of quantum chemistry for studying, can be used to judge some molecular properties, especially the molecular reactive activity. Molecular electrostatic potential has been widely applied to chemistry-related research. As the molecular electrostatic potential is determined by its properties, the electrostatic potential generated by each point of different molecules in their surrounding space is different. Therefore, we can use electrostatic potential to describe the nature of the molecule. We have proposed a new method to rapidly calculate the molecular electrostatic potential, and taken HF,H2O,C2H2,NH3 and CH4 as model molecules to calculate their electrostatic potential, and calculated the molecular electrostatic potential of ethanol,cyclopentadience,funan,oxazole,isoxazole, finally dozens of low-energy dimer structure of water were also calculated. And we discussed their electrostatic potential distribution. Where charges are directly calculated by atom-bond electronegativity equalization method atσπlevel, and the structure are optimized by MP2/6-311++G(d,p) method.The potential acting on an electron within a molecular has been recently defined by Yang and coworkers. Based on the PAEM, in terms of the classical turning points of electronic motion, a new method, molecular intrinsic characteristic contour, has been developed for describing molecular shape and face electron density. Along with development of our model, the electron density described by our model becomes more and more significant. Yang and coworkers have again proposed the molecular face theory. We have exhibited the graphics of their electrostatic potential distributions, which is based on the molecular intrinsic characteristic contour theory and the molecular face theory. The electrostatic potential distributions provides accurate, objective and visual images of molecular electrostatic properties. And the results have fairly consistency with the ab initio results. This lays the foundation for the electrostatic potential of the macromolecules.