Abstract
In current work, the authors have been applied the density functional theory (DFr) using B3LYP and CAM-B3LYP exchange-correlation functional with 6-31G* basis set on L-arginine p-nitrobenzoate monohydrate (LANB) molecule for the first bite to optimize its geometry and study the spectroscopic, electronic structure, nonlinear optical properties. Vibrational modes were found in good agreement with experimental reports. The calculated UV spectra by B3LYP/6-31G* and CAM-B3LYP/6-31G* level of theory shows an electronic transition at similar to 268 nm (4.63 eV) and 264 nm (4.70 eV) respectively. To explain the charge interaction taking place within the molecule highest occupied molecular orbital and lowest unoccupied molecular orbital were analyzed and their calculated energy gap was found to be 4.3 eV with an oscillatory strength 0.3796 at B3LYP/6-31G* level of theory. The dipole moment (mu(tot)), average and anisotropy of polarizability (alpha(tot), Delta alpha) and static and total first hyperpolarizability (beta(0), beta(tot)) values were calculated. The value of mu(tot) and beta(tot) are found to be 4.124D and 1.630 x 10(-30) esu and 4.127D and 1.133 x 10(-3) esu using B3LYP/6-31G* and CAM-B3LYP/6-31G* functional respectively. The value of,Otot is >4 and >3 times higher than prototype urea molecule calculated at both level of theory, respectively. The molecular electrostatic potential (MEP), frontier molecular orbital's (FMOs), global reactivity descriptors and thermodynamic properties are also calculated and discussed. The properties of LANB calculated at B3LYP are in good correlation with experimental than the CAM-B3LYP level of theory. The obtained results show that LANB molecule can be treated as a good candidate for nonlinear optical devices. (C) 2015 Elsevier B.V. All rights reserved.