A Study of Perturbations of the A1Σu+ State of Na2

High resolution Fourier spectrometry techniques have been used to study the A1Σ+u state, which is perturbed by the b3Πu state of the Na2 molecule. This study was achieved by means of exciting the B1Πu state from the X1Σ+g ground state by 4880 Å and 4965 Å lines of an Ar+ laser. The excitation is followed by collisional transfer energy produced between B1Πu and (2)1Σ+g states ν, which led to the population of the vibrational levels of the (2)1Σ+g state v. The analysis of the collision-induced system (2)1Σ+g −A1Σ+g enabled us to study, in detail, the perturbations of 11 vibrational levels from v = 0 to v = 10 of the A1Σ+u state.

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THE LYMAN BANDS OF MOLECULAR HYDROGEN

Canadian Journal of Physics ◽

10.1139/p59-070 ◽

1959 ◽

Vol 37 (5) ◽

pp. 636-659 ◽

Cited By ~ 269

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.

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The carbon monoxide flame bands

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1963.0178 ◽

1963 ◽

Vol 275 (1362) ◽

pp. 431-446 ◽

Cited By ~ 94

Keyword(s):

Carbon Monoxide ◽

Excited State ◽

High Resolution ◽

Energy Level ◽

Vibrational Level ◽

Ground State ◽

Fermi Resonance ◽

Absorption System ◽

Weak Absorption ◽

Vibrational Levels

The carbon monoxide flame bands have been photographed under high resolution from an afterglow source. Bands in the wavelength range 3100 to 3800 Å show a pattern which has been reproduced by calculations of the energies of high vibrational levels of the ground state of CO 2 . The structure of this energy level pattern is strongly affected by extensive Fermi resonance in the 1 Σ + g state. The spectrum is emitted by excited CO 2 molecules which radiate to the ground state from the lowest vibrational level and from the v ´ 2 = 1 level of a B 2 state. This excited state lies approximately 46 000 cm -1 above the lowest level of the ground state, an d has an OCO angle of 122 + 2° and a CO bond length of 1*246 ± 0*008 Å. Combination of these results with the work of other authors shows that the excited state is a 1 B 2 state, and that the carbon monoxide flame bands are associated with the weak absorption system of CO 2 at 1475 Å.

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Vibration-rotation bands of monodeuteroacetylene and the molecular dimensions

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1956.0035 ◽

1956 ◽

Vol 234 (1198) ◽

pp. 306-317 ◽

Cited By ~ 9

Keyword(s):

High Resolution ◽

Ground State ◽

Fermi Resonance ◽

Rotational Constants ◽

Bond Lengths ◽

Vibrational Levels ◽

Vibration Rotation ◽

Molecular Dimensions

Some vibration-rotation bands of monodeuteroacetylene have been measured with high resolution. Values have been derived for the coefficients α i relating the rotational constants in different vibrational levels, as follows: α 2 = + 0⋅00439, α 3 = + 0⋅00638, α 4 = — 0⋅0032 2 , α 5 = — 0⋅0011. Using the value B 00000 = 0⋅9910 5 cm -1 , also determined from many bands, a new value, B e = 0⋅9948, has been obtained leading to new estimates for the bond lengths r e CH = 1⋅058 Å, and r e C≡C = 1⋅205 0 . The l -doubling coefficient has been determined in two states, namely, q 00010 = 0⋅0056 and q 00003 = 0⋅0072. In the ground state the results are in accordance with a centrifugal stretching coefficient D = 0⋅7 x 10 -6 , but in some higher levels a markedly different value is derived, which may, however, arise through the effects of Fermi resonance.

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The Lyman and Werner Bands of Deuterium

Canadian Journal of Physics ◽

10.1139/p73-119 ◽

1973 ◽

Vol 51 (9) ◽

pp. 867-887 ◽

Cited By ~ 63

Author(s):

H. Bredohl ◽

G. Herzberg

Keyword(s):

High Resolution ◽

Ab Initio Calculations ◽

Vibrational Level ◽

Ground State ◽

Electronic Excitation ◽

Theoretical Calculations ◽

Dissociation Limit ◽

Excitation Energies ◽

Vibrational Levels ◽

Theory And Experiment

The Lyman and Werner bands of D2 have been measured under high resolution and their analysis has been extended. From this analysis the rotational and vibrational levels of the ground state of D2 have been evaluated up to the last vibrational level ν = 21 which lies only 2 cm−1 below the dissociation limit. The deviations of the observed ΔG(ν + 1/2) and Bv values from theoretical values given by Kolos and Wolniewicz on the basis of ab initio calculations are very small but systematic and are probably due to the neglect of nonadiabatic corrections in the theoretical calculations. Similar comparisons have been made for the lower vibrational levels of the B1Σu+ and C1Πu− states. Here the differences between theory and experiment are somewhat larger. The observed electronic excitation energies agree with the theoretical ones within 15 cm−1 for 1Σu+ and 8 cm−1 for 1Πu−.

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Ground state molecular parameters of phosphine, PH3, from the simultaneous analysis of the high-resolution infrared, microwave and submillimeterwave spectra

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19852480 ◽

1985 ◽

Vol 50 (11) ◽

pp. 2480-2492 ◽

Cited By ~ 12

Author(s):

Soňa Přádná ◽

Dušan Papoušek ◽

Jyrki Kauppinen ◽

Sergei P. Belov ◽

Andrei F. Krupnov ◽

...

Keyword(s):

Fourier Transform ◽

High Resolution ◽

Ground State ◽

Unitary Transformation ◽

Point Of View ◽

Acoustic Detection ◽

Molecular Parameters ◽

Microwave Spectrometer ◽

Fourier Transform Spectra ◽

First Time

Fourier transform spectra of the ν2 band of PH3 have been remeasured with 0.0045 cm-1 resolution. Ground state combination differences from these data have been fitted simultaneously with the microwave and submillimeterwave data to determine the ground state spectroscopical parameters of PH3 including the parameters of the Δk = ± 3n interactions. The correlation between the latter parameters has been discussed from the point of view of the existence of two equivalent effective rotational operators which are related by a unitary transformation. The ΔJ = 0, +1, ΔK = 0 (A1 ↔ A2, E ↔ E) rotational transitions in the ν2 and ν4 states have been measured for the first time by using a microwave spectrometer and a radiofrequency spectrometer with acoustic detection.

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