Proline and hydroxyproline zwitterions - an ab initio study

Ab initio calculations of proline and hydroxyproline zwitterions have been performed at the Hartree-Fock level using the 4-21++G basis set. The evaluated geometries have been compared to the corresponding X-ray parameters. The probable assignments for the experimental solid state vibrational spectra of proline and hydroxyproline based on the calculated ab initio frequencies and intensities were made. (C) 1997 Elsevier Science B.V.