title: Vibrational analysis of glycine radical: a comparative ab initio static and dynamic study.
abstract: We present quantum mechanical (QM) vibrational computations beyond the harmonic approximation for an organic molecule that exhibits both torsional and NH(2) out of plane type modes: the glycine radical. The effective second order perturbative, variational and variation-perturbation treatments-defined as static approaches-as well as vibrational analysis from ab initio molecular dynamics trajectories at 300 K and 600 K were performed using the B3LYP/6-31+G(d,p) description of the electronic structure. Theses schemes are compared in terms of prediction of fundamental transitions, simulation of the corresponding medium infrared (MIR) spectrum and extraction of substantial information for the understanding of chemical problems. The validity of the analyses is checked for a similar molecule, formamide, for which experimental data are available.
authors.affiliation: Groupe Chimie Théorique et Réactivité, ECP, IPREM UMR CNRS 5254, Université de Pau et des Pays de l'Adour 2, Rue Jules Ferry, F-64000, Pau, France. philippe.carbonniere@univ-pau.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Carbonniere
authors.forename: Alain
authors.initials: A
authors.lastname: Dargelos
authors.forename: Ilaria
authors.initials: I
authors.lastname: Ciofini
authors.forename: Carlo
authors.initials: C
authors.lastname: Adamo
authors.forename: Claude
authors.initials: C
authors.lastname: Pouchan
mesh_terms: D004583:Electrons; D005559:Formamides / Q000737:chemistry; D005998:Glycine / Q000737:chemistry*; D008958:Models, Molecular; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013696:Temperature; D014732:Vibration
chemical_list: D005559:Formamides; C031066:formamide; D005998:Glycine