Study of Renner--Teller, spin--orbit, and Fermi-resonance interactions in tilde X sup 2. Pi. ( v sub 1 v2 0) levels of NCO by stimulated emission pumping spectroscopy

Journal Article · Thu Oct 01 04:00:00 EDT 1992 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.463861· OSTI ID:7082443

Wu, M; Northrup, F J; Sears, T J ^[1]

---

1. Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973 (United States)

We report extensive measurements of rovibronic levels in the 020/100 and 040/120/200 Fermi-resonant polyads of NCO. The levels were accessed by the technique of stimulated emission pumping spectroscopy in a supersonic free jet expansion following excitation of bands in the {ital {tilde A}} {sup 2}{Sigma}{sup +}{minus}{ital {tilde X}} {sup 2}{Pi} spectrum of the radical. The data were analyzed in terms of an effective Hamiltonian which explicitly included reference to all the possible vibronic levels of {sup 2}{Pi} symmetry in the polyad under consideration. The effects of levels outside these were treated by perturbation theory. The model was successful in fitting the data close to the experimental measurement precision and the resulting parameters were interpreted in terms of the harmonic and anharmonic vibrational terms. The effective Renner--Teller coupling parameter in NCO varied with vibrational level; however, parameters describing the Fermi-resonance interaction were found to be constant for all the levels investigated.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7082443
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 97:7; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
664400 -- Experimentally Derived Information on Atomic & Molecular Properties-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COMPUTER CODES
COUPLING
ENERGY LEVELS
EXCIMER LASERS
EXCITED STATES
FERMI RESONANCE
GAS LASERS
HAMILTONIANS
INTERMEDIATE COUPLING
L-S COUPLING
LASERS
MATHEMATICAL OPERATORS
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PERTURBATION THEORY
QUANTUM OPERATORS
RADICALS
RESONANCE
ROTATIONAL STATES
SYMMETRY BREAKING
VIBRATIONAL STATES