THE b1Σ+–X3Σ− BAND SYSTEM OF NF

1966 ◽  
Vol 44 (10) ◽  
pp. 2251-2258 ◽  
Author(s):  
A. E. Douglas ◽  
W. E. Jones
Keyword(s):  
Ground State ◽  
Band System ◽  
High Dispersion ◽  
Rotational Analysis ◽  
Strong Band

If argon mixed with a small amount of NF3 is pumped rapidly through a mild discharge, a green glow is observed downstream from the discharge. This emission has been photographed with a high dispersion spectrograph and found to consist of a strong band with a head at 5 288 Å and a number of weaker bands. A rotational analysis of the bands has shown that they are the b1Σ+–X3Σ− bands of the NF molecule. The constants of the two states have been determined and it is found that for the ground state, ωe = 1 141.37 cm−1 and re = 1.317 3 Å.

ROTATIONAL ANALYSIS OF THE β BANDS OF PHOSPHORUS MONOXIDE

1959 ◽  
Vol 37 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Nand Lal Singh
Keyword(s):  
Ground State ◽  
Band System ◽  
Electronic States ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Fine Structures ◽  
Π State

The fine structures of three of the β bands of PO which occur near 3200 Å have been analyzed. The analysis shows that the upper state of this band system is a 2Σ and not a 2Π state as previously believed. The rotational constants of both electronic states have been determined and it is found that the ground state constants, previously determined from the γ bands, are incorrect.

THE ABSORPTION SPECTRUM OF CF2

1967 ◽  
Vol 45 (7) ◽  
pp. 2355-2374 ◽  
Author(s):  
C. Weldon Mathews
Keyword(s):  
Absorption Spectrum ◽  
Electronic State ◽  
Ground State ◽  
Band System ◽  
Electronic States ◽  
Vibrational Structure ◽  
Rotational Structure ◽  
Transition Moment ◽  
High Dispersion ◽  
Parallel Type

The absorption spectrum of CF2 in the 2 500 Å region has been photographed at high dispersion, and the rotational structure of a number of bands has been analyzed. The analysis of the well-resolved subbands establishes that these are perpendicular- rather than parallel-type bands, as previously assigned. Further analysis shows that the upper and lower electronic states are of 1B1 and 1A1symmetries respectively, corresponding to a transition moment that is perpendicular to the plane of the molecule. In the upper electronic state, r0(CF) = 1.32 Å and [Formula: see text], while in the ground state, r0(CF) = 1.300 Å and [Formula: see text]. An investigation of the vibrational structure of the band system has shown that the vibrational numbering in ν2′ must be increased by one unit from earlier assignments, thus placing the 000–000 band near 2 687 Å (37 220 cm−1). A search between 1 300 and 8 500 Å showed two new band systems near 1 350 and 1 500 Å which have been assigned tentatively to the CF2 molecule.

ROTATIONAL ANALYSIS OF THE VISIBLE BAND SYSTEM OF THE BiF MOLECULE

1962 ◽  
Vol 40 (9) ◽  
pp. 1077-1084 ◽  
Author(s):  
T. A. Prasada Rao ◽  
P. Tiruvenganna Rao
Keyword(s):  
Band System ◽  
High Dispersion ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Visible Band ◽  
System A

A rotational analysis of five bands, (1,0), (0,0), (0,1), (0.2), and (0,3), of the visible band system A of BiF has been carried out by photographing the bands under high dispersion (1.25 Å/mm). The analysis has shown that the bands arise from a 0+(3Σ−)–0+(3Σ−) transition. The rotational constants for the upper and lower states of the system are obtained.

A NEW BAND SYSTEM OF THE P2 MOLECULE ANALOGOUS TO THE LYMAN–BIRGE–HOPFIELD BANDS OF N2

1958 ◽  
Vol 36 (5) ◽  
pp. 565-570 ◽  
Author(s):  
A. E. Douglas ◽  
K. Suryanarayana Rao
Keyword(s):  
Excited States ◽  
Ground State ◽  
Singlet State ◽  
Band System ◽  
Excited Singlet State ◽  
Lower State ◽  
High Dispersion ◽  
Electron Configuration ◽  
Excited Singlet ◽  
New System

Five bands of a new band system of P2 have been photographed at high dispersion and analyzed. The upper state of the system is a 1П0 state and lies lower than any previously known excited singlet state. The lower state of the new system is the ground state of P2 and the analysis of the new bands has given improved constants for this state. The new system appears to be the analogue of the Lyman–Birge–Hopfield bands of N2. The electron configuration of the low excited states of P2 and of related molecules is discussed.

The electronic spectrum of F2

1976 ◽  
Vol 54 (13) ◽  
pp. 1343-1359 ◽  
Author(s):  
E. A. Colbourn ◽  
M. Dagenais ◽  
A. E. Douglas ◽  
J. W. Raymonda
Keyword(s):  
Absorption Spectrum ◽  
Ground State ◽  
Band System ◽  
Rydberg States ◽  
Rotational Analysis ◽  
Interaction Energies ◽  
Rydberg Series ◽  
Rotational Constants ◽  
Vibrational Levels ◽  
Ionic States

The absorption spectrum of F2 in the 780–1020 Å range has been photographed at sufficient resolution to allow a rotational analysis of many bands. A large number of vibrational levels of three ionic states have been observed and their rotational constants determined. Many perturbations in the rotational structure caused by the interaction between the three states have been investigated and the interaction energies determined. The rotational and vibrational structures of a few Rydberg states have also been analyzed in detail but no Rydberg series have been identified. The difficulties in assigning the observed states are discussed. A 1Σu+ – X1Σg+ emission band system has been observed in the 1100 Å region. An analysis of the bands of this system has allowed us to determine the term values and rotational constants of all the vibrational levels of the ground state with ν ≤ 22. The dissociation energy, D0(F2), is found to be greater than 12 830 and is estimated to be 12 920 ± 50 cm−1.

ULTRAVIOLET SPECTRA OF LiH AND LiD

1957 ◽  
Vol 35 (10) ◽  
pp. 1204-1214 ◽  
Author(s):  
R. Velasco
Keyword(s):  
Excited State ◽  
Ground State ◽  
Band System ◽  
Electronic States ◽  
High Dispersion ◽  
Dissociation Energies ◽  
Near Ultraviolet ◽  
Path Lengths ◽  
Vibrational Constants ◽  
Π State

The absorption spectra of LiH and LiD have been observed in the near ultraviolet with high dispersion and absorbing path lengths up to 16 meters. A new band system has been found in each molecule involving the ground state and a 1Π excited state. Rotational and vibrational analyses of this system have been carried out and rotational and vibrational constants for the upper state have been determined. The observed breaking off of the rotational structure of the bands of this B1Π—X1Σ+ system has been interpreted as due to predissociation by rotation. With this assumption very accurate dissociation limits of the B1Π state have been obtained. From these dissociation limits the dissociation energies of the three known electronic states of LiH and LiD have been calculated. In particular the dissociation energies (D0) of the ground states of LiH and LiD have been found to be 2.4288 ± 0.0002 ev. and 2.4509 ± 0.0010 ev., respectively.

Spectrum of AsS. I. Analysis of the A′2Π3/2–X2Π3/2 Band System

1971 ◽  
Vol 49 (10) ◽  
pp. 1249-1254 ◽  
Author(s):  
Midori Shimauchi
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Ground State ◽  
Band System ◽  
Vibrational Analysis ◽  
Quartz Tube ◽  
Rotational Analysis ◽  
Vibrational Constants

The emission spectrum of the AsS radical, excited in a quartz tube by a 2450 MHz oscillator, was photographed on a high resolution spectrograph from 2450 to 6900 Å. Seven bands around 6000 Å showing clear rotational structures were chosen for the first rotational analysis of the AsS spectrum. The bands were found to arise from a 2Π3/2–2Π3/2 transition. The rotational and vibrational constants of the two states derived from the present work are consistent with the previous vibrational analysis of the A′2Π3/2–X2Π3/2 system. The constants of the upper doublet component of the ground state, X2Π3/2, are ωe = 562.40 cm−1, ωexe = 2.02 cm−1, re = 2.0216 Å; the constants of the A′2Π3/2 state are ΔG′(1/2) = 403.37 cm−1, ν0,0 = 18 621.21 cm−1, re = 2.2500 Å.

Analyse vibrationnelle et rotationnelle de la transition A2Σ+–X2Πi de la molécule 63Cu80Se

1976 ◽  
Vol 54 (16) ◽  
pp. 1664-1668 ◽  
Author(s):  
Y. Lefebvre ◽  
J. L. Bocquet
Keyword(s):  
Band System ◽  
High Dispersion ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Visible Band ◽  
Π State

High dispersion vibrational and rotational analysis of a 63Cu80Se visible band system has been performed.The presence of a splitting proportional to [Formula: see text] in each observed subsystem indicates that these bands arise from a transition from a 2Σ state (with γ-type doubling) to a 2Π state. This hypothesis allows us to derive specific molecular constants of these two states.

The electronic spectrum of the CS+ molecular ion: rotational analysis and perturbation effects in the A2Πi–X2Σ+ transition

1978 ◽  
Vol 56 (5) ◽  
pp. 587-600 ◽  
Author(s):  
D. Gauyacq ◽  
M. Horani
Keyword(s):  
Carbon Disulfide ◽  
Ground State ◽  
Valence Electron ◽  
Band System ◽  
Local Perturbation ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Molecular Ion ◽  
Vibrational Levels ◽  
The Difference

A new emission spectrum in the red region (6000–8000 Å) has been recorded from a low pressure hot cathode discharge through carbon disulfide. This band system has been assigned to the A2Πi–X2Σ+ transition of the CS+ molecular ion on the basis of the rotational analysis and comparison with other nine valence-electron molecules. Molecular constants have been obtained by direct least squares fits of the line frequencies to the difference of the eigenvalues of standard 2Π and 2Σ+ matrices.A local perturbation in the A2Πi (ν = 5) state has been studied quantitatively. The position of the perturbing vibrational level in the X2Σ+ state has been determined within a few centimetre−1. This study gave a consistent set of molecular constants for the ground state of CS+ and allowed a partial deperturbation treatment of the observed vibrational levels of the excited A2Πi state.Numerous bands are also observed in the 4000 Å region. A discussion is given concerning the possible assignment of bands at 4059 and 4110 Å to the CS+B2Σ+–A2Πi (0,0) transition.

ROTATIONAL ANALYSIS OF THE γ BAND SYSTEM OF THE NS MOLECULE

1951 ◽  
Vol 29 (2) ◽  
pp. 174-185 ◽  
Author(s):  
P. B. Zeeman
Keyword(s):  
Ground State ◽  
Band System ◽  
Rotational Analysis ◽  
First Order ◽  
Quartz Spectrograph ◽  
Concave Grating

The band heads of the NS spectrum discovered in 1932 by Fowler and Bakker have been remeasured on plates taken on a large quartz spectrograph and on first order grating plates. The (0,0) and (0,1) γ bands have been photographed in the 6th, 8th, and 9th orders of a 21 ft. concave grating, and a rotational analysis of these bands has been carried out. For the ground state (2II) it was found that [Formula: see text] = 0.77364 cm−1, [Formula: see text] = 0.00612, and A = 223.03 cm.−1 For the upper state the value [Formula: see text] = 0.82670 was obtained.

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