An Abstract

Abstract :Atom bond electronegativity equalization method (ABEEM) is developed from
density functional theory (DFT) and electronegativity equalization principle , where chemical bonds are explicitly considered. ABEEM does not introduce any experimental datum and has pure theoretical and computational characteristics. We select more than 200 model molecules using unified standards with representativeness and comprehensiveness. The geometries are 3 optimized by MP2/ 6 - 31 G because these calculated geometries are usually accurate ; the  charge distributions are obtained via Mulliken population analysis of HF/ STO - 3 G calculations;and the ABEEM parameters of some main group atoms (including the single , double and triple bonding states) and bonds in their molecular systems are determined through a regression and least2square fitting procedure. The obtained valence2state electronegativities of the atoms are very close to other proposed electronegativity scales ; The negative charge point of CO molecule was computed to be C(contrary to ab initio result) , which is consistent with the experimental fact ; And the negativeness or positiveness of the atomic charge of a molecule is not completely determined by the atomic electronegativity.
Keywords :atom2bond electronegativity equalization method ; density funcitonal theory ; electronegativity ; hardness ; charge