The and band systems of the CS2+ ion

1976 ◽  
Vol 54 (19) ◽  
pp. 1969-1978 ◽  
Author(s):  
Walter J. Balfour
Keyword(s):  
Bond Length ◽  
Electronic States ◽  
Electron Excitation ◽  
Fermi Resonance ◽  
A Value ◽  
Medium Resolution ◽  
Resonance Interactions

The [Formula: see text] and [Formula: see text] emission systems of the CS2+ ion have been photographed at medium resolution following controlled electron excitation of CS2 gas. Vibrational analyses have been performed for both systems. The (0010)–(0010) transitions of the [Formula: see text] and [Formula: see text] subsystems lie at 21 107 and 20 843 cm−1, respectively. Evidence is presented for Fermi resonance interactions between (100) and (020) levels in the [Formula: see text] and [Formula: see text] electronic states. The rotational structures of six partially resolved subbands of the [Formula: see text] system have been studied and a value of 1.615 Å obtained for the C—S bond length of CS2+ in the [Formula: see text] state.

Renner−Teller and Fermi Resonance Interactions for the v3= 1 and v7= 2 Vibronic Levels in the A2Πuand X2ΠgElectronic States of HC4H+

2011 ◽  
Vol 115 (34) ◽  
pp. 9365-9369 ◽  
Author(s):  
Ranjini Raghunandan ◽  
Fabio J. Mazzotti ◽  
Aaseef M. Esmail ◽  
John P. Maier
Keyword(s):  
Fermi Resonance ◽  
Resonance Interactions

THE MICROWAVE SPECTRUM AND MOLECULAR STRUCTURE OF CHF2Cl

1962 ◽  
Vol 40 (1) ◽  
pp. 61-73 ◽  
Author(s):  
David B. McLay ◽  
C. R. Mann
Keyword(s):  
Bond Length ◽  
Electric Quadrupole ◽  
Microwave Spectrum ◽  
Molecular Structures ◽  
Moments Of Inertia ◽  
A Value ◽  
Principal Axes ◽  
Quadrupole Coupling ◽  
Out Of Plane ◽  
Tetrahedral Angle

Sufficient Q- and R-branch rotational transitions have been measured in the microwave spectrum of the asymmetric top molecule CHF2Cl to determine the moments of inertia Ia, Ib, and Ic for each of the three isotopic species C12HF2Cl35, C12HF2Cl37, and C13HF2Cl35. The value of Ia+Ic−Ib, which should depend only upon the out-of-plane co-ordinate of the fluorine atoms, is sufficiently constant to give a very accurate value for the co-ordinate of 1.08524 ± 0.00006 Å but involves some variations which limit the accuracy of determining molecular structures by isotopic substitutions. The components of the nuclear electric quadrupole coupling dyadics in the principal axes systems for the moments of inertia ellipsoids have been calculated accurately from the hyperfine structure of the C12HF2Cl35,37 spectra. In both cases, eQVaa+eQVbb+eQVcc = 0 and the ratio of any component for Cl35 to the same component for Cl37 is equal to 1.269 within the experimental error. The low-field Stark splitting of the 00,0 → 11,0 transition indicates a dipole moment component μc = 1.5 debyes while the absence of a-type transitions indicates a value for μa, which is less than 0.1 μc. The C—Cl bond length and the angle between this bond and the a-axis have been calculated by Kraitchman's formulae for isotopic substitution to be 1.747 ± 0.002 Å and 14.3 ± 0.2°. This angle and the values of eQVaa, eQVbb, and eQVcc lead to eQVzz = eQq = −71.5 ± 0.3 Mc/s and quadrupole coupling asymmetry parameter η = −0.012 ± 0.006, which indicates very little π-electron character. If the C—H bond length is assumed to be 1.095 ±.015 Å and the angle H—C—Cl is assumed to be 108 ± 1°, then the calculated values for the C—F bond length and for the angle F—C—F are 1.350 ±.003 Å and 107.0 ± 0.4°, a value considerably less than the tetrahedral angle. The values for bond lengths, bond angles, and nuclear electric quadrupole coupling components are compared with those in other halogenated methanes.

scholarly journals Measurement of the A-Value of the Intersystem Transition in Al II at 2670 Å: Å Progress Report

1984 ◽  
Vol 86 ◽  
pp. 163-166
Author(s):  
B. Carol Johnson ◽  
H.S. Kwong
Keyword(s):  
Cross Sections ◽  
Radiative Decay ◽  
Transition Probabilities ◽  
Radiative Transition ◽  
Electron Excitation ◽  
Spectral Lines ◽  
Metastable Level ◽  
Astrophysical Plasmas ◽  
Atomic Ions ◽  
A Value

Ratios of intensities of spectral lines produced in the radiative decay of collisionally-excited levels of atomic ions are versatile indicators of electron density in astrophysical plasmas when one of the lines involves a metastable level (see the review by Feldman 1981 and references therein). Radiative transition probabilities (A-values) and electron excitation cross sections are necessary for accurate, quantitative analyses of these plasmas. The work reported here is part of a program of measurements of astrophysically interesting A-values and radiative lifetimes (see the review by Smith et al. 1984); until we began, such anaylyses of astrophysical plasmas depended upon unconfirmed calculated A-values.

scholarly journals Electron excitation of the Schumann–Runge continuum, longest band, and second band electronic states in O2

2011 ◽  
Vol 134 (6) ◽  
pp. 064311 ◽  
Author(s):  
Daisuke Suzuki ◽  
Hidetoshi Kato ◽  
Mizuha Ohkawa ◽  
Kazutoshi Anzai ◽  
Hiroshi Tanaka ◽  
...  
Keyword(s):  
Electronic States ◽  
Electron Excitation

Emission Spectrum of the PO Molecule. Part II.2Σ–2Σ Transitions

1971 ◽  
Vol 49 (24) ◽  
pp. 3180-3200 ◽  
Author(s):  
R. D. Verma ◽  
M. N. Dixit ◽  
S. S. Jois ◽  
S. Nagaraj ◽  
S. R. Singhal
Keyword(s):  
Emission Spectrum ◽  
Ionization Potential ◽  
Dissociation Energy ◽  
Ground State ◽  
Rydberg States ◽  
Electronic States ◽  
Electronic Transitions ◽  
A Value ◽  
Upper Limit ◽  
First Ionization Potential

Rotational structure of emission bands of the PO molecule in the region 5300–3800 Å is analyzed. The spectrum is attributed to 5 electronic transitions A2Σ+–B2Σ+, F2Σ+–B2Σ+, G2Σ+–B2Σ+, H2Σ+–B2Σ+, and I2Σ+–B2Σ+, where F, G, H, and I are the new electronic states and A and B are the upper states of the well-known γ and β bands respectively. Practically all the new 2Σ states are found to be perturbed. A qualitative account of these perturbations together with a deperturbation of certain levels is given. A number of cases of predissociation are also observed. This predissociation is attributed to the presence of 4Πi, and A′2Σ+ states, which dissociate to the ground state atomic products. From this an upper limit of the dissociation energy of the ground state of PO is determined to be D0 = 49 536 cm−1. The A, D, E, G, H, and I states of this molecule are assigned as Rydberg states corresponding to the σ4s, π4p, δ3d, σ4p, σ3d, and σ5s orbitals, respectively. From them a value of 67 570 cm−1 is evaluated for the first ionization potential of PO. All the electronic states established for this molecule are described in terms of electron configurations.

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