L-Alaninium Maleate (LAM) an efficient nonlinear optical material was synthesized and grown from aqueous solution. The crystal structure of LAM was solved by direct method using SHELXS-97 and it’s found that it crystallizes in orthorhombic crystal system having non-centrosymmetry with P21212 space group. The alaninium residue forms N-H...O and O-H..O hydrogen bonds with malaete anion and the later form O-H..O hydrogen bonds with each other. Density functional theory computations of equilibrium geometry and the first order hyperpolarizability of the crystal were calculated. The optimized geometric bond lengths and bond angles obtained by using DFT (B3LYP/6-31G (d,p)) show good agreement with the experimental data.
