title: Treatment of nonlinear optical properties due to large amplitude anharmonic vibrational motions: umbrella motion in NH3.
abstract: A general reduced dimensionality finite field nuclear relaxation method for calculating vibrational nonlinear optical properties of molecules with large contributions due to anharmonic motions is introduced. In an initial application to the umbrella (inversion) motion of NH(3) it is found that difficulties associated with a conventional single well treatment are overcome and that the particular definition of the inversion coordinate is not important. Future applications are described.
authors.affiliation: Department of Chemistry and Institute of Computational Chemistry, University of Girona, Campus de Montilivi, 17071 Girona, Catalonia, Spain. josepm.luis@udg.edu
authors.forename: Josep M
authors.initials: JM
authors.lastname: Luis
authors.forename: Heribert
authors.initials: H
authors.lastname: Reis
authors.forename: Manthos
authors.initials: M
authors.lastname: Papadopoulos
authors.forename: Bernard
authors.initials: B
authors.lastname: Kirtman
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D007700:Kinetics; D013816:Thermodynamics; D014732:Vibration
chemical_list: D000641:Ammonia