Abstract
Amino acids are the building block of proteins so that some three amino acids with different forms were subjected to spectroscopic analyses. D-alanine, L-asparagine and glycine were studied by XRD, FTIR and molecular modeling. Structural geometry data are introduced based on FTIR and DFT molecular modeling. B3LYP/6-31g** shows comparable results with FTIR experimental spectra, accordingly this model has been utilized to describe the structural properties of the studied amino acids. Bond lengths, bond angles are obtained. No significant differences were observed as one compares non hydrated and hydrated amino acids bond lengths. While bond angles show significant differences between non- and hydrated amino acids.