Biomaterial Database

Vibrational energy levels for CH4 from an ab initio potential. 2001

D W Schwenke, and H Partridge

NASA Ames Research Center, Moffett Field, CA 94035-1000, USA. schwenke@pegasus.arc.nasa.gov

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.

UI	MeSH Term	Description	Entries
D008697	Methane	The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D001256	Astronomy	The science concerned with celestial bodies and the observation and interpretation of the radiation received in the vicinity of the earth from the component parts of the universe (McGraw Hill Dictionary of Scientific and Technical Terms, 5th ed)
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D014732	Vibration	A continuing periodic change in displacement with respect to a fixed reference. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Vibrations
D055580	Astronomical Phenomena	Aggregates of matter in outer space, such as stars, planets, and comets; their properties; and the processes they undergo.	Astronomical Processes,Astronomic Concepts,Astronomic Phenomena,Astronomic Phenomenon,Astronomic Process,Astronomic Processes,Astronomical Concepts,Astronomical Process,Astrophysical Concepts,Astrophysical Phenomena,Astrophysical Phenomenon,Astrophysical Processes,Astronomic Concept,Astronomical Concept,Astrophysical Concept,Concept, Astronomic,Concept, Astronomical,Concept, Astrophysical,Concepts, Astronomic,Concepts, Astronomical,Concepts, Astrophysical,Phenomena, Astronomic,Phenomena, Astronomical,Phenomena, Astrophysical,Phenomenon, Astronomic,Phenomenon, Astrophysical,Process, Astronomic,Process, Astronomical,Processes, Astronomic,Processes, Astronomical,Processes, Astrophysical
D019411	Clinical Laboratory Techniques	Techniques used to carry out clinical investigative procedures in the diagnosis and therapy of disease.	Clinical Laboratory Test,Clinical Laboratory Testing,Clinical Laboratory Diagnoses,Clinical Laboratory Testings,Clinical Laboratory Tests,Diagnoses and Laboratory Examinations,Diagnosis, Laboratory,Laboratory Diagnosis,Laboratory Examinations and Diagnoses,Laboratory Techniques, Clinical,Clinical Laboratory Technique,Diagnose, Clinical Laboratory,Laboratory Diagnoses,Laboratory Technique, Clinical,Laboratory Test, Clinical,Laboratory Testing, Clinical,Technique, Clinical Laboratory,Test, Clinical Laboratory,Testing, Clinical Laboratory