Electronic Structure of 1,3-dicarbomethoxy4,6-benzenedicarboxylic acid: Density functional approach

Abstract

Structural optimization of 1,3-dicarbomethoxy4,6-benzenedicarboxylic acid single crystal was performed by minimizing the forces which act on the atoms. The optimized geometry was used to perform the theoretical study of electronic properties, electronic charge density and optical properties. Electronic structure, electronic charge density and optical properties were investigated using the full potential linear augmented plane wave based on the first-principles density functional theory (DFT). The exchange correlation (XC) effects are taken in to account by Local Density Approximation (LDA), Generalized Gradient Approximation (GGA) and modified Becke Johnson (MBJ) potential. The band structure shows that the calculated compound has an indirect band gap of 2.99, 3.05 and 3.93 eV for LDA, GGA and mBJ respectively. The electron charge densities were also analyzed and discussed. The charge densities indicate that bonding between H-O, C-C and O-O is mainly covalent and the bonding between O is mainly ionic. The complex dielectric function, refractive index, energy-loss spectrum and reflectivity have been calculated.