title: Vibrational energy levels for CH4 from an ab initio potential.
abstract: Many areas of astronomy and astrophysics require an accurate high temperature spectrum of methane (CH4). The goal of the present research is to determine an accurate ab initio potential energy surface (PES) for CH4. As a first step towards this goal, we have determined a PES including up to octic terms. We compare our results with experiment and to a PES based on a quartic expansion. Our octic PES gives good agreement with experiment for all levels, while the quartic PES only for the lower levels.
authors.affiliation: NASA Ames Research Center, Moffett Field, CA 94035-1000, USA. schwenke@pegasus.arc.nasa.gov
authors.forename: D W
authors.initials: DW
authors.lastname: Schwenke
authors.forename: H
authors.initials: H
authors.lastname: Partridge
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D019411:Clinical Laboratory Techniques; D004734:Energy Metabolism; D008697:Methane / Q000737:chemistry*; D013696:Temperature; D014732:Vibration
chemical_list: D008697:Methane