Quantum-mechanical calculations of magnesium aspartate-arginine structure and spectroscopic characteristics

Theoretical calculations of magnesium aspartate-arginine (Mg[Asp-Arg]) structure and spectroscopic characteristics have been performed in the gas phase with the gaussian 98 software package using density functional theory (DFT) at the B3PW91 level. The 6-31+G* basis set was selected due to their reasonable quality and size. The comparison with corresponding results for magnesium aspartate-glycine (Mg[Asp-Gly]) is presented. NMR and IR measurements were carried out and obtained experimental 1H and 13C chemical shifts and IR spectra are compared with calculated spectral parameters.