Study of The Electronic Structure of di-Cyclobutadiene Molecule by Using Density Functional Theory

Abstract

This work reports a theoretical study to investigate the electronic structure and electronic properties for unsaturated organic molecules group by using density functional theory (DFT) at B3LYP level with basis sets 6-31G(d,p). Cyclobutadiene is original molecule and then two Cyclobutadiene was linked, Studied the effect of linking on original cyclobutadiene molecule discussed based on the calculated electronic properties. The electronic properties included total energy, energy gap, ionization potential, electron affinity, have been found a striking variation in these values for these molecules, with comprehensive analysis of the calculated highest-occupied molecular orbital (HOMO) and lowest-unoccupied molecular orbital (LUMO) energies. These calculations have performed using Gaussian 09 package.