“…The complete understanding of the optical properties of amino acid crystals, as well as other organic crystals, still requires more information. Some complexes of glycine with HCl [5,6], lithium sulfate [7], H 3 PO 3 [8], H 2 SO 4 [9], CaNO 3 [10], CoBr 2 [11], LiNO 3 [12], H 2 SO 4 [13,14], sodium nitrate [15], benzoyl glycine [16] form single crystals, but some of these are reported to have NLO property and some are reported not to have NLO property. Effects of hydrogen bonds on optical non-linearities of complex crystals have been studied [17,18].…”