The 1Π–X1Σ+ band system of AsP

1970 ◽  
Vol 48 (23) ◽  
pp. 2842-2851 ◽  
Author(s):  
L. Harding ◽  
W. E. Jones ◽  
K. K. Yee

The rotational analysis of the 2–0, 1–0, 0–0, 0–1, and 0–2 bands of the molecule AsP is reported. The band system corresponds to a 1Π–1Σ+ transition. Molecular constants of the lower and upper states are found to be[Formula: see text]Several perturbations have been found in the upper vibrational levels.

1978 ◽  
Vol 56 (5) ◽  
pp. 587-600 ◽  
Author(s):  
D. Gauyacq ◽  
M. Horani

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.


1975 ◽  
Vol 53 (14) ◽  
pp. 1321-1326 ◽  
Author(s):  
M. Carleer ◽  
M. Herman ◽  
R. Colin

A rotational analysis has been performed on the 0–0 band of the A2Π–X2Σ+ transition of the BeBr molecule photographed at high resolution in emission from a beryllium hollow cathode in the presence of bromine vapor. The following principal molecular constants have been determined:[Formula: see text]


1942 ◽  
Vol 20a (6) ◽  
pp. 71-82 ◽  
Author(s):  
A. E. Douglas ◽  
G. Herzberg

In a discharge through helium, to which a small trace of benzene vapour is added, a new band system of the type 1Π – 1Σ is found which is shown to be due to the CH+ molecule. The R(0) lines of the 0–0, 1–0, and 2–0 bands of the new system agree exactly with the hitherto unidentified interstellar lines 4232.58, 3957.72, 3745.33 Å, thus proving that CH+ is present in interstellar space. At the same time this observation of the band system in absorption shows that the lower state 1Σ is the ground state of the CH+ molecule. The new bands are closely analogous to the 1II – 1Σ+ BH bands. The analysis of the bands leads to the following vibrational and rotational constants of CH+ in its ground state: [Formula: see text], Be″ = 14.1767, αe″ = 0.4898 cm.−1. The internuclear distance is re″ = 1.1310∙10−8 cm. (for further molecular constants see Table V). From the vibrational levels of the upper 1Π state the heat of dissociation of CH+ can be obtained within fairly narrow limits: D0(CH+) = 3.61 ± 0.22 e.v. From this value the ionization potential of CH is derived to be I(CH) = 11.13 ± 0.22 e.v. The bearing of this value on recent work on ionization and dissociation of polyatomic molecules by electron impacts is briefly discussed.


1976 ◽  
Vol 54 (13) ◽  
pp. 1343-1359 ◽  
Author(s):  
E. A. Colbourn ◽  
M. Dagenais ◽  
A. E. Douglas ◽  
J. W. Raymonda

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.


1975 ◽  
Vol 53 (19) ◽  
pp. 2221-2231 ◽  
Author(s):  
O. Appelblad ◽  
A. Lagerqvist

A blue band system of CuO, a 2Σ−–X2Πi transition, has been rotationally analyzed. The relative branch intensities differ from those of a pure 2Σ–2Π transition. The molecular constants of all the known states of CuO are given.


1967 ◽  
Vol 45 (8) ◽  
pp. 2805-2807 ◽  
Author(s):  
P. Ramakoteswara Rao ◽  
K. V. S. R. Apparao

The C band system of 63Cu81Br, lying in the region 3 900–4 600 Å, has been photographed in emission under high resolution and rotational analysis of the (2–0), (1–0), (0–0), (0–1), (0–2), and (1–3) bands carried out. The system is shown to involve a 1Σ(C1Σ)–1Σ(X1Σ) transition. The molecular constants of 63Cu81Br obtained from this fine-structure analysis are as follows:[Formula: see text]


1976 ◽  
Vol 54 (16) ◽  
pp. 1664-1668 ◽  
Author(s):  
Y. Lefebvre ◽  
J. L. Bocquet

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.


1979 ◽  
Vol 57 (7) ◽  
pp. 1051-1058 ◽  
Author(s):  
R. Colin

Six bands of the b1Σ+–X3Σ− transition of the PBr molecule have been observed in a microwave discharge of PBr3 + He. High resolution spectra have allowed the rotational analysis of the 0–0 and 1–1 bands. The principal molecular constants obtained are:X3Σ−: P79Br; ωe = 458.35 cm−1, Be = 0.16067 cm−1; P81Br; ωe = 457.78 cm−1, Be = 0.15958 cm−1; re = 2.1714 Å.B1Σ+: P79Br; ωe = 485.47 cm−1, Be = 0.16509 cm−1; P81Br; ωe = 483.84 cm−1, Be = 0.16399 cm−1; re = 2.1421 Å and Te = 11779.75 cm−1.


1972 ◽  
Vol 50 (19) ◽  
pp. 2265-2276 ◽  
Author(s):  
J. M. Berthou ◽  
B. Pascat ◽  
H. Guenebaut ◽  
D. A. Ramsay

Rotational analyses have been carried out for the 0ν′20–000 bands of the [Formula: see text] electronic transition of PH2 with ν′2 = 1–8. Approximately 1000 lines have been assigned. The earlier analysis of the 000–000 band has been extended and improved molecular constants obtained. The Hamiltonian used for this band does not fit the excited state levels with [Formula: see text]. Term values are therefore given for all observed levels. Empirical formulas are presented which give approximate fits to the higher levels. Numerous rotational perturbations are found in the excited state. Perturbations up to 0.6 cm−1 are also found in the 000 level of the excited state. These latter perturbations can only be caused by the higher vibrational levels of the ground state.


1984 ◽  
Vol 62 (12) ◽  
pp. 1328-1335 ◽  
Author(s):  
Tetsuo Suzuki ◽  
Shuji Saito ◽  
Eizi Hirota

The dye laser excitation spectrum of the [Formula: see text] vibronic band of HCF was observed between 18 190 and 18 422 cm−1 with Doppler-limited resolution. The observed spectrum exhibits a number of anomalies. The perturbations observed for Ka = 1 levels are well explained by an electronic Coriolis interaction with highly excited vibrational levels of the ground electronic state. Other anomalies are difficult to analyze, because most of them are local without showing any systematic frequency shifts. Some of the perturbed lines are found to have large Zeeman effects; thus the perturbations are ascribed to interactions with the lowest triplet state. The rotational analysis of the observed spectrum leads to the following molecular constants for HCF in the Ã1A(010) state: ν0 = 18 298.6927(71), B + C = 2.26710(34), B − C = 0.074(15), and the electronic Coriolis coupling term [Formula: see text], all in cm−1 with standard errors in parentheses.


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