ROTATIONAL ANALYSIS OF THE VISIBLE EMISSION BANDS OF THE PbF MOLECULE

1964 ◽  
Vol 42 (4) ◽  
pp. 690-695 ◽  
Author(s):  
K. Madhusudana Rao ◽  
P. Tiruvenganna Rao

The rotational structure of the (0, 0), (0, 1), (0, 2), and (1, 0) bands of the visible band system (A–X1) of PbF has been examined in the second order of a 21-ft concave grating spectrograph having a dispersion of 1.25 Å/mm. A rotational analysis of the bands has led to a determination of the rotational constants of the upper and lower states. From consideration of electron configurations it is suggested that the system arises from a [Formula: see text] transition which is a case c equivalent of [Formula: see text].

1967 ◽  
Vol 45 (11) ◽  
pp. 3663-3666 ◽  
Author(s):  
K. M. Lal ◽  
B. N. Khanna

The emission spectrum of the A–X system of the PbBr molecule in the region 4 600–5 900 Å has been obtained in the second order of a 21-ft concave grating spectrograph (15 000 lines per inch) with a dispersion of 1.25 Å/mm. A rotational analysis of four bands—(3, 2), (2, 2), (3, 1), and (4, 1)—of this system has been done, leading to the determination of the following rotational constants:[Formula: see text]The system appears to be similar to the A-X system of the PbCl molecule in the visible region, and a [Formula: see text] transition has been suggested.


1962 ◽  
Vol 40 (9) ◽  
pp. 1077-1084 ◽  
Author(s):  
T. A. Prasada Rao ◽  
P. Tiruvenganna Rao

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.


1992 ◽  
Vol 70 (5) ◽  
pp. 291-294 ◽  
Author(s):  
Sheila Gopal ◽  
M. Singh ◽  
G. Lakshminarayana

The emission spectrum of Si130Te was excited by microwave discharge (2450 MHz) in a sealed quartz tube. The A1Π–X1Σ+ band system (3100–3900 Å) (1 Å = 10−10 m) photographed under high resolution on a 10.6 m Ebert grating spectrograph. The rotational analysis of 32 bands was carried out, which led to the determination of the accurate vibrational and rotational constants. The rotational structure belonging to ν′ > 9 levels appear to be perturbed.


1972 ◽  
Vol 50 (18) ◽  
pp. 2206-2210 ◽  
Author(s):  
O. Nath Singh ◽  
I. S. Singh ◽  
O. N. Singh

The rotational analysis of the three bands (1,0), (0,0), and (0,1) of the B–X2 system of PbF has been carried out. The bands have been excited in a transformer discharge and photographed in the second order of a 35 ft concave grating spectrograph. The analysis has shown that the bands arise from a 2Σ+–2Π3/2 transition. The rotational constants of the upper and lower states have been determined.


1968 ◽  
Vol 46 (17) ◽  
pp. 1991-1992
Author(s):  
K. M. Lal ◽  
B. N. Khanna

The rotational structure of the A–X system of the PbBr molecule has been recorded in the second order of a 35-ft concave grating spectrograph at a dispersion of 0.33 Å/mm and the analysis of four bands (3, 2), (2, 2), (4, 2), and (4, 1) has been done. In all, four branches have been observed for each of the bands and they have been explained as the P and R branches due to Pb79Br and Pb18Br. The following constants were obtained:[Formula: see text]


1969 ◽  
Vol 47 (15) ◽  
pp. 1639-1641 ◽  
Author(s):  
O. N. Singh ◽  
M. P. Srivastava ◽  
I. S. Singh

The rotational analysis of the four bands (0,0), (0,1), (0,2), and (1,0) of the A–X1 system of PbF has been carried out. The bands have been excited in a transformer discharge and photographed in the second order of a 35-ft concave grating spectrograph. The analysis has shown that the bands arise from a [Formula: see text] transition. The rotational constants of the upper and lower states have been determined.


1973 ◽  
Vol 51 (2) ◽  
pp. 125-143 ◽  
Author(s):  
R. W. Martin ◽  
A. J. Merer

Rotational analysis of over 50 sub-bands of three emission transitions of 74GeF has given vibrational and rotational constants for the four lowest-lying electronic states of GeF. One of these is a 4Σ− state in Hund's case (a), where all four spin components have been identified. Extensive perturbations between this 4Σ− state and the B2Σ+ state have been analyzed in detail: the two states appear to interact mainly by a second-order mechanism through the so far uncharacterized σπ22Σ+ state, but the surprisingly large J dependence of the perturbation matrix element suggests that another mechanism, possibly involving the ground state, may contribute. Further perturbations, where the lines show an unusual intensity enhancement, appear in those sub-bands with B2Σ+ ν = 4 as upper state.


1966 ◽  
Vol 44 (10) ◽  
pp. 2241-2245 ◽  
Author(s):  
P. Ramakoteswara Rao ◽  
K. V. S. R. Apparao

The E band system of 63Cu127I, lying in the region 3 700 to 4 700 Å, has been photographed in emission under high resolution. Rotational analysis of the (0–4), (0–3), (0–2), (0–1), (0–0), (1–1), (1–0), (2–0), and (3–2) bands has been made. The electronic transition involved is found to be 1Σ (E1Σ)–1Σ(X1Σ). The rotational constants obtained are as follows:[Formula: see text]


1959 ◽  
Vol 37 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Nand Lal Singh

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.


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.


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