Density Functional Theory (DFT) Analysis of L-Phenylalanine Maleate (LPM)

L-Phenylalanine maleate (LPM) an efficient Nonlinear optical material is synthesized and analyzed by Density Functional Theory. In LPM molecule the amino acid moiety exists in cationic form and the maleic acid in the mono-ionized state.DFT calculation with B3LYP/6-31G(d,p) basis set has been used to determine ground state molecular geometries (bond lengths and bond angles). HOMO and LUMO energies show that charge transfer occurs within the molecule and the energy gap is found to be -0.05244 a.u. The large second order NLO response of the molecule is indicated by the charge transfer from L-phenylalanine to maleate moiety through the hydrogen bond.