C. I. Frum

The infrared emission spectrum of gas-phase C60 (buckmisterfullerene)

Abstract The gas-phase infrared spectrum of C 60 has been observed in emission with the National Solar Observatory Fourier transform spectrometer at Kitt Peak. Bands attributable to the C 60 molecule are found at 527.1, 570.3, 1169.1 and 1406.9 cm −1 . Additional emission features are tentatively assigned to C 70 or combination bands of C 60 . A new, strong emission is observed at 1010.2 cm −1 belonging to an unknown molecule. None of these features can be associated with any of the strong emission bands observed so far in astronomical sources.

Fourier transform emission spectroscopy at 13 μm: Vibration–rotation spectrum of SiS

The vibration–rotation emission spectrum of the high temperature molecule SiS was recorded with a Fourier transform spectrometer. The observation of a high resolution emission spectrum at 13 μ (750 cm−1) is unusual but we believe this technique is generally applicable to high temperature species. Seven bands (1–0 through 7–6) of the main isotopic form, 28Si32S, were observed along with three bands (1–0, 2–1, and 3–2) for each of the minor species, 29Si32S, 30Si32S, and 28Si34S. Mass‐reduced Dunham parameters, including Watson’s correction due to the breakdown of the Born–Oppenheimer approximation, were derived from the data.

Fourier transform emission spectroscopy of the A′3Π-X3Σ− transition of PtO

Abstract A new 3 Π electronic state of PtO has been observed between 7100 and 8015 cm −1 above the ground state. Three independent electronic systems connecting Ω ′ = 0 + , 1, and 2 in the upper state to Ω ″ = 1 in the ground state have been recorded in emission from a Pt hollow cathode with the Fourier transform spectrometer associated with the McMath solar telescope at Kitt Peak. We interpret these three transitions as arising from the spin components of a new A ′ 3 Π- X 3 Σ − transition in Hunds case (a) notation. Molecular constants (including Ω-doubling parameters) for the new electronic state have been determined from the analysis of the data.

Fourier transform emission spectroscopy of BeF2 at 6.5 μm

The high resolution infrared emission spectrum of BeF2 was observed. The fundamental antisymmetric stretching mode ν3 and numerous hot bands involving ν1 and ν2 were found near 1550 cm−1 by Fourier transform spectroscopy. Eight vibration–rotation bands were rotationally analyzed and the spectroscopic constants are reported. The equilibrium beryllium fluorine distance (re) was found to be 1.372 9710(95) A in BeF2.

Electronic structure of polyatomic systems determined with first-order correlation orbitals. Coupled cluster calculations on lithium cyanide

Abstract First-order correlation orbitals and the coupled cluster method were employed together with an extended Gaussian basis set to evaluate the relative energies of three isomers of lithium cyanide. The most stable linear LiNC structure has an energy 0.75 kcal/mol lower than the T-shape structure and 2.34 kcal/mol lower than the linear LiCN structure. The first result remains in accord with the recently established lower limit of 0.34 kcal/mol.

Fourier transform detection of the vibration-rotation bands of IF

Abstract High resolution absorption spectra of the IF molecule in the X 1 Σ + ground state have been observed with the Kitt Peak Fourier transform spectrometer in a F 2 /I 2 flame. Accurate wavenumber measurements (±0.0002 cm −1 ) were made for the 1-0, 2-1 and 2-0 bands and molecular constants were derived.