First Order Hyperpolarizability and Homo-Lumo Analysis of L-Arginine Maleate (LArM) by Density Functional Theory Methods

Quantum mechanical calculation is an efective tol to study the molecular behavior. L-Arginine maleate(LArM) an eficient NLO material is analyzed quantum mechanicaly by ab inito and Density Functional(DFT) method. It’s found that first order hyperpolarizabilty of the molecule is 6.3061527×10- 30esu and the large value of hyperpolarization along zdirection shows asubstantial delocalization of charges in these directions. Highest Ocupied Molecular Orbital (HOMO) energy and Lowest Unocupied Molecular (LUMO) energy were calculated and molecular energy gap is found to be 0.04638 a.u. This HOMO is mainly localized on the malate anion so that its energy is indicative of the donating character and LUMO is localized on L- Arginine cation. Strong donating group leads to high Polarizabilty values. Second Harmonic Generating eficiency depends on high hyperpolarizabilty of the material.