Potential Energy Surface Scan Studies and NBO Analysis of L-Alanylglycine Crystal: A Vibrational Approach

Abstract

Quantum and classical studies of vibrational motion of CH 5 + on a global potential energy surface obtained from a novel ab initio direct dynamics approach Abstract. Vibrational spectral analysis of L-Alanylglycine (L-Ala-GIy) is carried out using NIR FT-Raman and FT-IR spectroscopy, supported by density functional theory (DPT) calculations to obtain the equilibrium geometry, bonding features and harmonic vibrational frequencies. The assignments of the \dbrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). Potential energy surface (PES) scan studies has also been carried out by ab initio calculations with B3LYP/6-311+G** basis set. The natural bond orbital (NBO) analysis confirms the occurrence of strong intermolecular hydrogen bonding in the molecule.