Born–Oppenheimer breakdown in the ground state of carbon monoxide: A direct reduction of spectroscopic line positions to analytical radial Hamiltonian operators

1992 ◽  
Vol 70 (1) ◽  
pp. 40-54 ◽  
Author(s):  
John A. Coxon ◽  
Photos G. Hajigeorgiou
Keyword(s):  
Carbon Monoxide ◽  
Ground State ◽  
Direct Reduction ◽  
Direct Determination ◽  
Quantum Mechanical ◽  
Rotational Line ◽  
Molecular Constants ◽  
Full Account ◽  
Radial Wave ◽  
Line Positions

A collection of 10 866 of the most precise ground-state (X1Σ+) vibration–rotational and pure rotational line positions of four carbon monoxide isptopomers (12C16O, 12C18O, 13C16O, and 13C18O) is employed simultaneously in a direct determination of the radial Hamiltonian operator in compact analytical form. The 22-parameter isotopically self-consistent operator takes full account of the Born–Oppenheimer breakdown and its quantum-mechanical eigenvalues represent all the available spectroscopic line positions of CO isotopomers to within the experimental uncertainties. Rayleigh–Schrödinger perturbation theory is employed to calculate quantum-mechanical molecular constants of rotation (Bν – Mν) for nine common isotopomeric forms of CO. Together with the quantum-mechanical vibrational eigenvalues these are fully consistent with the exact eigenvalues obtained by direct solution of the radial wave equation. The set of constants is expected to provide an accurate prediction of line positions of CO isotopomers that have not yet been experimentally observed.

High-resolution spectroscopy of the (000)–(000) band of the CaOD radical

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1200-1205 ◽  
Author(s):  
Mingguang Li ◽  
John A. Coxon
Keyword(s):  
High Resolution ◽  
Gas Phase ◽  
Ground State ◽  
Measurement Accuracy ◽  
Isotope Effects ◽  
Spin Rotation ◽  
High Resolution Spectroscopy ◽  
Rotational Line ◽  
Measured Line ◽  
Line Positions

The [Formula: see text] (000)–(000) band of the gas-phase CaOD radical has been rotationally analyzed using high-resolution laser spectroscopy. The technique of intermodulated fluorescence was employed to resolve the small spin-rotation splittings in the ground state. The measurement accuracy of the rotational line positions was 0.003 cm−1. The measured line positions have been employed in a least-squares estimation of the molecular constrants for both electronic states. Isotope relations between the constants of CaOH and CaOD are examined, and the constants AD and γ for the Ã2Π(000) level were separated using isotope effects.

High-resolution emission bands of the A2Π – X2Π system of SO+

1984 ◽  
Vol 62 (12) ◽  
pp. 1792-1800 ◽  
Author(s):  
J. L. Hardwick ◽  
Yin Luo ◽  
D. H. Winicur ◽  
J. A. Coxon
Keyword(s):  
High Resolution ◽  
Ground State ◽  
Band System ◽  
Equilibrium Constants ◽  
Molecular Constants ◽  
Visible Band ◽  
Medium Resolution ◽  
Self Consistent ◽  
Measured Line ◽  
Line Positions

The A2Πi → X2Πr visible band system of SO+ has been recorded photographically at high resolution. Molecular constants for the A and X states have been fitted to the measured line positions of the 0–5, 0–6, 1–5, and 1–6 bands. Λ-type doubling was resolved completely for most of the lines of the 2Π1/2 – 2Π1/2 sub-bands, and has led to the first reported values of the splitting constants p′ and p″. All the estimated constants have been merged with constants obtained previously from medium-resolution spectra for other levels of the X2Π ground state. A self-consistent set of constants is reported for ν′ = 0 and 1 and for ν = 4–9, together with revised equilibrium constants.

Fourier transform spectroscopy of the Herzberg I bands of O2

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1101-1108 ◽  
Author(s):  
K. Yoshino ◽  
J. E. Murray ◽  
J. R. Esmond ◽  
Y. Sun ◽  
W. H. Parkinson ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Wavelength Region ◽  
Rotational Line ◽  
Molecular Constants ◽  
Absorption Bands ◽  
Weakly Bound ◽  
Vibrational Levels ◽  
J 13 ◽  
Line Positions ◽  
Made In

Fourier transform spectroscopic measurements of the absorption bands of the Herzberg I system [Formula: see text] of O2, have been made in the wavelength region 240–270 nm. Rotational line positions are determined with an accuracy of 0.005 cm−1, and rotational term values are presented for the vibrational levels, ν = 4–11. Molecular constants of these levels are also presented. Interactions with the [Formula: see text] state are observed at J = 13 of the ν = 4 level, at J = 16 of the ν = 7 level, and at J = 15 and 24 of the ν = 9 level of the [Formula: see text] state. Another interaction around J = 10 of the ν = 11 level might result from the weakly bound 3Πu state.

Molecular Constants of the Ground State of the I2 Molecule

1951 ◽  
Vol 19 (9) ◽  
pp. 1210-1211 ◽  
Author(s):  
D. H. Rank ◽  
William. M. Baldwin
Keyword(s):  
Ground State ◽  
Molecular Constants

Global fitting of the vibrational-rotational line positions of the acetylene molecule

2000 ◽  
Author(s):  
Oleg M. Lyulin ◽  
Valery I. Perevalov ◽  
Sergey A. Tashkun ◽  
Jean-Luc Teffo
Keyword(s):  
Rotational Line ◽  
Acetylene Molecule ◽  
Line Positions ◽  
Global Fitting

STRUCTURE, STABILITY, AND ELECTRONIC PROPERTIES OF LARGE FULLERENES

1993 ◽  
Vol 07 (26) ◽  
pp. 4305-4329 ◽  
Author(s):  
C.Z. WANG ◽  
B.L. ZHANG ◽  
K.M. HO ◽  
X.Q. WANG
Keyword(s):  
Total Energy ◽  
Electronic Properties ◽  
Ground State ◽  
Relative Stability ◽  
Chemical Reactivity ◽  
Structure Stability ◽  
Quantum Mechanical ◽  
Efficient Scheme ◽  
Ground State Structures ◽  
Fullerene Clusters

The recent development in understanding the structures, relative stability, and electronic properties of large fullerenes is reviewed. We describe an efficient scheme to generate the ground-state networks for fullerene clusters. Combining this scheme with quantum-mechanical total-energy calculations, the ground-state structures of fullerenes ranging from C 20 to C 100 have been studied. Fullerenes of sizes 60, 70, and 84 are found to be energetically more stable than their neighbors. In addition to the energies, the fragmentation stability and the chemical reactivity of the clusters are shown to be important in determining the abundance of fullerene isomers.

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