Density Function Theory B3LYP/6-31G**Calculation of Geometry Optimization and Energies of Donor-Bridge-Acceptor Molecular System

Abstract

Theoretical B3LYP/6-31G (d , p) density functional theory has been employed to examine the electronic properties of donor-bridge-acceptor molecular system and determine the energies. The electronic states of the system has been calculated depends on Koopman's theorem under the orbital-vertical theory. The results show that the functional used in the description of the studied molecular system has been proved its validity in calculating the HOMO and LUMO energies and it is a suitable for studying the geometry optimization for the organic molecular system, there are localized orbitals in different parts of the D-B-A molecular system in which that satisfy important property for the D-B-A system to show model new electronic properties as an Aviram-Ratner.