Electronic spectrum of H2O+

1976 ◽  
Vol 54 (20) ◽  
pp. 2028-2049 ◽  
Author(s):  
H. Lew
Keyword(s):  
Emission Spectrum ◽  
Electronic Spectrum ◽  
Ground State ◽  
Energy Levels ◽  
Bond Distance ◽  
Electronic States ◽  
Wavelength Region ◽  
Astrophysical Interest ◽  
Vibrational Levels ◽  
Wave Numbers

Many bands of the [Formula: see text] electronic emission spectrum of H2O+, occurring in the wavelength region 4000–7500 Å, have been analyzed. These include bands that have been observed in the tails of comets. The wavelengths and wave numbers of all assigned lines are tabulated. Accurate rotational constants for the first three bending vibrational levels of the ground state are given, as well as energy levels in the upper and lower electronic states. The O—H bond distance and the H—O—H angle in the [Formula: see text] (0, 0, 0) level are found to be 0.9988 Å and 110.46° respectively. Some predicted microwave and infrared lines that may be of astrophysical interest are included.

The Emission Spectrum of PtO between 3800 and 4500 Å

1975 ◽  
Vol 53 (19) ◽  
pp. 1991-1999 ◽  
Author(s):  
Rosemary Scullman ◽  
Ulf Sassenberg ◽  
Christer Nilsson
Keyword(s):  
Emission Spectrum ◽  
Ground State ◽  
Lower State ◽  
Vibrational Levels ◽  
New System

A new system belonging to the emission spectrum of PtO has been found in the region of 3800–4500 Å. This system has the earlier known X1Σ ground state as the lower state and a hitherto unknown 1Σ state, here designated the D1Σ state, as the upper state. The four lowest vibrational levels of the D1Σ state were rotationally analyzed. Of these levels, the [Formula: see text] level seems to be unperturbed although the v′ = 1, 2, and 3 levels are strongly perturbed.

Zeeman effects in the band System of sulfur dioxide

1976 ◽  
Vol 54 (2) ◽  
pp. 186-196 ◽  
Author(s):  
J. C. D. Brand ◽  
J. L. Hardwick ◽  
D. R. Humphrey ◽  
Y. Hamada ◽  
A. J. Merer
Keyword(s):  
Sulfur Dioxide ◽  
Ground State ◽  
Band System ◽  
Zeeman Effect ◽  
Electronic States ◽  
Vibrational Levels ◽  
Asymmetric Rotor ◽  
Most Probable Explanation ◽  
Rotational Coupling ◽  
Singlet Transition

Bands of the [Formula: see text] system of sulfur dioxide appear as structured absorption superimposed on an apparent continuum. A portion of this System between 3250 and 3000 Å has been recorded in a magnetic field and is found to exhibit a strong Zeeman effect, contrary to expectation for a singlet-singlet transition between bent states of an asymmetric rotor. Line shift and broadening is observed in relatively low fields (< 3 kG), and the spectra become diffuse in fields of ~ 10 kG. The possibility is considered that the magnetic moment in the à state results from rotational coupling of singlet electronic states but it appears unlikely that the angular momentum so developed is sufficient to account for the observations. The most probable explanation of the magnetic sensitivity is that the à state couples with a background of interacting vibrational levels of the ground state and low lying states of the triplet manifold.

The electronic emission spectrum of triatomic hydrogen. I. Parallel bands of H3 and D3 near 5600 and 6025 Å

1980 ◽  
Vol 58 (8) ◽  
pp. 1238-1249 ◽  
Author(s):  
I. Dabrowski ◽  
G. Herzberg
Keyword(s):  
Interstellar Medium ◽  
Emission Spectrum ◽  
Detailed Analysis ◽  
Ground State ◽  
Emission Band ◽  
Rydberg States ◽  
Electronic States ◽  
Molecular Constants ◽  
Additional Band ◽  
Rydberg Electron

A spectrum of triatomic hydrogen and deuterium was first discovered by means of an emission band with diffuse rotational structure near 5600 Å. An additional band of similar but much better resolved structure was subsequently observed near 6025 Å. The detailed analysis of these two bands for both H3 and D3 is described in this paper. Both bands are [Formula: see text] bands of a symmetric top; their structure establishes beyond doubt that triatomic hydrogen has a D3h structure in its Rydberg states. The molecular constants in upper and lower states are close to those in the ground state of H3+ (or D3+) in accordance with the assumption that these states are Rydberg states in which a single electron moves around a H3+ or D3+ core. The predicted states of such a Rydberg electron in a field of D3h symmetry account very well for the observed electronic states, both those involved in the [Formula: see text] bands described here and those involved in the [Formula: see text] bands to be discussed in subsequent papers of this series. The lowest state of the Rydberg electron 2p2E′ is unstable and dissociates to H2 + H in their ground states. It is this state that causes predissociation in the two lower states 2s2A1′and 2p2A2″ of the two [Formula: see text] bands here under discussion. The predissociation of 2s2A1′ is vibronically allowed and fairly strong such that all lines have widths of about 7 cm−1 for D3 and 30 cm−1 for H3. The predissociation of the 2p2A2″ state is vibronically forbidden and occurs only on account of ro-vibronic interaction. H3+ ions are assumed to be present in the interstellar medium. When they recombine with electrons they must necessarily emit the spectra described in this series of papers.

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.

Further results relating to the electronic spectrum of 175Lu16O

1986 ◽  
Vol 64 (3) ◽  
pp. 246-251 ◽  
Author(s):  
A. Bernard ◽  
C. Effantin
Keyword(s):  
Least Squares ◽  
Electronic Spectrum ◽  
Ground State ◽  
Rotational Analysis ◽  
Least Squares Fitting ◽  
Fitting Procedure ◽  
Vibrational Levels ◽  
Unique Band ◽  
Π State ◽  
New System

Further results are presented concerning the three known systems of the molecule LuO; i.e., A2Π, B2Π, C2Σ+ → X2Σ+. The observed wavenumbers in each of the 12 analyzed bands are reduced using an iterative, least squares fitting procedure. Rotational constants are given for vibrational levels ν = 0 and 1 in the C state and up to ν = 7 in the X and B states. The 1–1 band of the A → X system is partly analyzed. These new calculations confirm level B to be the 3/2 component of a 2Π state; but they give no such confirmation for the identification of the A level, whose 2Π nature is well established, as the 1/2 component of the same state.Moreover, a unique band at 5120 Å that cannot be classified into any of the three known systems is described and attributed to a new system of LuO. A partial rotational analysis is made showing that the band corresponds to a transition involving the level ν = 0 in the ground state. The nature of the upper state is discussed.

THE ELECTRONIC STATES OF CIS- AND TRANS-ACETYLENE

1959 ◽  
Vol 37 (4) ◽  
pp. 700-707 ◽  
Author(s):  
H. Howard ◽  
G. W. King
Keyword(s):  
Ground State ◽  
Energy State ◽  
Energy Levels ◽  
Electronic States ◽  
Electronic Energy ◽  
Class A ◽  
Allowed Transition ◽  
Form Part ◽  
Electronic Energy Levels ◽  
Cis And Trans

The electronic energy levels of cis- and trans-bent planar centrosymmetric acetylene molecules, with [Formula: see text] and r cc = 1.383 Å, have been calculated by the LCAO/ASMO/CI procedure. The lowest energy state that can spectroscopically combine with the linear ground state is found to be of symmetry class Au belonging to the trans-bent molecule and to lie at 4.58 ev above the ground state. This compares favorably with the experimentally observed electronic transition of lowest energy which is of type (1Au−1∑g+) and at 5.24 ev. The lowest-energy allowed transition to a cis-bent state of these dimensions is at 9.39 ev, and hence this may not form part of the unanalyzed system of bands in the 2000–1500 Å region, as has been suggested. However, a transition to a trans-bent state of type (1Bu−1∑g+) is predicted to fall in this region. The energies of other electronic states are discussed in relation to the observed absorption systems of acetylene.

Vibronically induced Jahn–Teller progressions in the electronic spectrum of iridium hexafluoride

1968 ◽  
Vol 46 (15) ◽  
pp. 1721-1724 ◽  
Author(s):  
J. C. D. Brand ◽  
G. L. Goodman
Keyword(s):  
Electronic Spectrum ◽  
Excited States ◽  
Electric Dipole ◽  
Ground State ◽  
Electronic States ◽  
Electronic Transitions ◽  
Electrostatic Forces ◽  
First Approximation ◽  
Jahn Teller

The absorption of IrF6 vapor between 0.7 and 1.3 μ consists of three distinct electronic transitions connecting the Γ8g ground state with higher Γ6g, Γ8g, and Γ7g states of the (5d f2g)3 configuration. In first approximation, Jahn–Teller forces vanish in the two Γ8g states, while the Γ6g and Γ7g states involve Kramers magnetic degeneracy, which cannot be split by electrostatic forces. Accordingly, no splittings of the ν2(eg) or ν5(f2g) excited states are observed in these spectra, but short progressions in ν5 do appear in the electric-dipole-allowed, vibronic parts of these transitions. These progressions are considered to show that Jahn–Teller anharmonicity can be induced by admixtures of odd-parity, orbitally degenerate electronic states, i.e. by the same mechanism through which these transitions derive their electric-dipole intensity.

Electronic spectrum of the BF molecule

1970 ◽  
Vol 48 (4) ◽  
pp. 432-452 ◽  
Author(s):  
R. B. Caton ◽  
A. E. Douglas
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Ionization Potential ◽  
Electronic Spectrum ◽  
Excited States ◽  
Electronic Absorption ◽  
Rydberg States ◽  
Electronic States ◽  
Rydberg Series ◽  
Absorption And Emission

The electronic absorption and emission spectrum of BF has been photographed at high resolution from 900 to 11 000 Å. In this work, many new electronic states have been found and corrections have been made to earlier work. The ionization potential has been determined to be between 89 635 and 89 680 cm−1, with the most probable value being 89 650 cm−1. Tables of the vibrational and rotational constants of all the known states of BF are presented. All but two of the excited states of BF have been classified as Rydberg states and have been assigned to Rydberg series. The interactions between the various Rydberg states are discussed.

Rotational Analysis of the A–X System of the SiCl Molecule

1971 ◽  
Vol 49 (4) ◽  
pp. 407-411 ◽  
Author(s):  
S. R. Singhal ◽  
R. D. Verma
Keyword(s):  
Ground State ◽  
Electronic States ◽  
Rotational Structure ◽  
Spin Coupling ◽  
Quartz Tube ◽  
Rotational Analysis ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Molecular Constants ◽  
Vibrational Levels

The A–X system of the SiCl molecule in the region 4500–6400 Å has been excited by an r.f. discharge through a mixture of argon and a trace of SiCl4 vapor, flowing through a quartz tube. Several red degraded and double headed bands with ν′ = 0, 1, 2, and 3 have been observed and the rotational structure of the 0-5, 0-6, 0-7, 0-8, 0-9, 0-10, 1-9, and 1-10 bands has been analyzed. The analysis shows that the bands arise from a 2Σ–2Π transition, 2Π being the ground state of the molecule. The molecular constants have been determined for both the electronic states. The spin coupling constant, Aν, of the X2Π vibrational levels has been found to follow an equation[Formula: see text]

THE 1Πu ← 1Δg ELECTRONIC SPECTRUM OF NCN

1967 ◽  
Vol 45 (4) ◽  
pp. 1439-1450 ◽  
Author(s):  
H. W. Kroto
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Electronic Spectrum ◽  
Electronic Absorption ◽  
Ground State ◽  
Flash Photolysis ◽  
Bond Distance ◽  
Splitting Parameter

The analysis of a new electronic absorption spectrum observed during the flash photolysis of cyanogen azide, NCN3, in the region 3 327 Å indicates that the spectrum belongs to a 1Πu–1Δg transition of NCN. The 1Δg state is metastable with respect to the [Formula: see text] ground state. The bond distance in the 1Δg state is 1.228 5 Å. The value of the Renner splitting parameter, εω2, for the 1Πu state has been determined as −84.2 cm−1.

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