Investigation of the rovibrational levels of the B3Πg state of 14N2 molecule above the dissociation limit N(4S) + N(4S) by Fourier transform spectrometry

1990 ◽  
Vol 68 (11) ◽  
pp. 1257-1261 ◽  
Author(s):  
F. Roux ◽  
F. Michaud
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Emission Spectrum ◽  
Dissociation Limit ◽  
Fourier Transform Spectrometry ◽  
Strong Intensity ◽  
Vibrational Levels ◽  
Dissociation Threshold

Rotational analyses of vibrational levels of the B3Πg state, located above the dissociation threshold N(4S) + N(4S) were performed from a high-resolution emission spectrum recorded by Fourier transform spectrometry. Strong intensity perturbations were observed in the B3Πg vibrational levels ν′ = 13, 14, and 15.

THE LYMAN BANDS OF MOLECULAR HYDROGEN

1959 ◽  
Vol 37 (5) ◽  
pp. 636-659 ◽  
Author(s):  
G. Herzberg ◽  
L. L. Howe
Keyword(s):  
High Resolution ◽  
Vibrational Level ◽  
Ground State ◽  
Molecular Hydrogen ◽  
Equilibrium Constants ◽  
Dissociation Limit ◽  
Vibrational Levels ◽  
State Formula ◽  
Single Formula ◽  
Vibrational Constants

The Lyman bands of H2 have been investigated under high resolution with a view to improving the rotational and vibrational constants of H2 in its ground state. Precise Bv and ΔG values have been obtained for all vibrational levels of the ground state. One or two of the highest rotational levels of the last vibrational level (v = 14) lie above the dissociation limit. Both the [Formula: see text] and ΔG″ curves have a point of inflection at about v″ = 3. This makes it difficult to represent the whole course of each of these curves by a single formula and therefore makes the resulting equilibrium constants somewhat uncertain. This uncertainty is not very great for the rotational constants for which we find[Formula: see text]but is considerable for the vibrational constants ωe and ωexe for which three-, four-, five-, and six-term formulae give results diverging by ± 1 cm−1. The rotational and vibrational constants for the upper state [Formula: see text] of the Lyman bands are also determined. An appreciable correction to the position of the upper state is found.

High resolution absorption spectrum of nitric oxide (NO) in the region of the first ionization limit

1976 ◽  
Vol 54 (20) ◽  
pp. 2074-2092 ◽  
Author(s):  
E. Miescher
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Ionization Energy ◽  
Dissociation Limit ◽  
Matrix Elements ◽  
Rydberg Series ◽  
Isotopic Species ◽  
Vibrational Levels ◽  
Energy Formula ◽  
Ionization Limit

The absorption spectrum of cold NO gas has been photographed at high resolution between 1400 and 1250 Å for two isotopic species. Resolved bands of the Rydberg series converging to vibrational levels of the 1Σ+ ground state of NO+ are studied. They include nf–X bands up to n = 15 and ns–X bands up to n = 11, all of which show sharp rotational structure. The higher members of the np–X series are generally very diffuse with only npσ being sufficiently sharp to show broadened rotational lines. Also mostly diffuse are the ndδ–X bands. The bands ndσ, π–X are not observed. The rapidly (n−3) narrowing structure of the nf complexes is discussed and the ionization energy [Formula: see text] accurately determined by extrapolation of selected rotational lines. Interactions between Rydberg states are numerous, s ~ d mixing produces a strong effect above n = 6 when (n + 1)s levels fuse with nl levels into 'supercomplexes'. Matrix elements are given for observed 8f ~ 9s and 6f ~ 6dδ interactions.Valence levels are not observed above the ionization energy, except for the repulsive state A′2Σ+ arising from the first dissociation limit and seemingly assuming Rydberg character at molecular internuclear distance. Observed anomalies are qualitatively discussed.

Two New Band Systems in the Near Ultraviolet Spectrum of N2

1975 ◽  
Vol 53 (19) ◽  
pp. 2198-2209 ◽  
Author(s):  
P. K. Carroll ◽  
K. V. Subbaram
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Rydberg State ◽  
Molecular Nitrogen ◽  
Ultraviolet Spectrum ◽  
Dissociation Limit ◽  
Ultraviolet Emission ◽  
Weak Band ◽  
Near Ultraviolet ◽  
Unusual Type

Two new weak band systems have been identified under high resolution in the near ultraviolet emission spectrum of molecular nitrogen. They are found to arise from a transition from a hitherto unknown 1Πg state, which it is proposed to call k, to the a′ 1Σu− and w1Δu states. The upper state is interpreted as the 1ΠgRydberg state of configuration … (1πu)4 (3σg) 3dπg. Straightforward treatment of the data by conventional methods gives B0d = 1.906 cm−1, B1d = 1.824 cm−1, T0 = 113 630.87 cm−1, and ΔG1/2 = 2305.92 cm−1. Only the d levels, i.e., the levels corresponding to the 1Πg− component, are observed and the absence of the c levels is attributed to an unusual type of predissociation involving the predicted stable 1Σg+ state which goes to the dissociation limit 2D + 2D (14.522 eV) and the 3Σg− state which arises at the limit 4S + 2P (13.332 eV). A new level at 117 661.11 cm−1 with a Bd value of 1.695 cm−1 is identified as v = 2 of the y1Πg state. A strong homogeneous interaction is found to be occurring between the new k1Πg state and the y1Πg state. A deperturbation calculation is carried out and yields the following deperturbed constants: k1Πg: Be = 1.959 cm−1; αe = 0.031 cm−1; re = 1.109 Å; T0 = 113 723.58 cm−1; ΔG1/2 = 2182.32 cm−1, y1Πg: Be = 1.739 cm−1; αe = 0.017 cm−1; re = 1.177 Å; Te = 114 314.36 cm−1; ωe = 1906.43 cm−1; αexe = 37.51 cm−1.

The absorption spectrum of C2H2 around ν1 + ν3: energy standards in the 1.5 μm region and vibrational clustering

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1241-1250 ◽  
Author(s):  
Q. Kou ◽  
G. Guelachvili ◽  
M. Abbouti Temsamani ◽  
M. Herman
Keyword(s):  
Absorption Spectrum ◽  
Fourier Transform ◽  
High Resolution ◽  
Rotational Analysis ◽  
Vibrational Assignment ◽  
Calibration Standards ◽  
Vibrational Levels ◽  
Vibrational Transitions ◽  
The Fourier Transform ◽  
Anharmonic Couplings

We have recorded the Fourier transform absorption spectrum of acetylene, C2H2, at high resolution, around 6500 cm−1. The positions of the strongest rovibrational lines are measured with respect to the rovibrational lines in 3-0 of CO. They provide secondary calibration standards in that range with an accuracy of 3 × 10−4 cm−1. The rotational analysis of the data gives evidence of five vibrational levels of [Formula: see text] symmetry, in addition to the bright combination level (1010000). This is demonstrated to strictly fit the predicted anharmonic resonance pattern in that region, which permits the vibrational assignment of those extra transitions. Study of the relative intensities of the reported vibrational transitions suggests the need to include new quartic anharmonic couplings. This is supported by the rovibrational analysis of the cold bands around 8500 cm−1, involving the (1110000) bright level, which is also presented.

Molecular constants of 128Te2

1991 ◽  
Vol 69 (1) ◽  
pp. 57-61 ◽  
Author(s):  
O. Babaky ◽  
K. Hussein
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
High Precision ◽  
Fluorescence Spectra ◽  
Fourier Transform Spectroscopy ◽  
Molecular Constants ◽  
Vibrational Levels ◽  
Potential Curves

Laser-excited fluorescence spectra of 128Te2 were studied by high-resolution Fourier transform spectroscopy, the sources of excitation used were Ar+ and Kr+ laser lines at 5145, 4880, 4579, and 4131 Å. (1 Å = 10−10 m). Transitions involving three upper states, [Formula: see text] and [Formula: see text] and three lower states [Formula: see text] and [Formula: see text] have been identified. The molecular constants of the lower states were determined with high precision. These constants were used to obtain the Rydberg–Klein–Rees potential curves of the states for vibrational levels ν up to 42. Limited results were also obtained for the upper states [Formula: see text] and [Formula: see text]

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