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.

High resolution absorption studies of the b1Πu ← X1Σg+ system of nitrogen

1969 ◽  
Vol 47 (5) ◽  
pp. 563-589 ◽  
Author(s):  
P. K. Carroll ◽  
C. P. Collins
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Triplet State ◽  
Rotational Structure ◽  
Dissociation Limit ◽  
Rydberg Series ◽  
Absorption Studies ◽  
Vibrational Levels ◽  
Single Transition ◽  
Made In

New high resolution studies of the absorption spectrum of N2 have been made in the region 1015–795 Å. Analyses are given of 25 non-Rydberg bands of the type 1Πu–X1Σg+. It is shown that all of these bands, which include the i, j, b, l, m, p, and q groups of Worley, together with several new bands not previously observed, can be assigned to a single transition the upper state of which is called b1Πu. The pronounced irregularities in the vibrational and rotational structure of the b state are attributed to a homogeneous interaction with the first member (n = 3) of the ---(3σg) npπu, 1Πu Rydberg series. This perturbation is discussed in the accompanying paper by Dressier who recognized its importance in the interpretation of the spectrum. Diffuseness in the rotational lines of several bands at lower ν was observed and is attributed to predissociation by a triplet state, probably the C′ 3Πu state which goes to the 4S + 2D dissociation limit. Three levels of the b state show measurable Λ-type doubling which can be interpreted as caused by interaction with vibrational levels of the first member (n = 4) of the --(3σg) npσu, 1Σu+ Rydberg series. The assignment of 28 non-Rydberg 1Σu+ levels, including the b′, g, f, r, s, and t "states", to a single 1Σu+ state which is called b′, is also briefly discussed.

Autoionization resonances in the Eu I absorption spectrum and a new determination of the ionization potential

1975 ◽  
Vol 342 (1628) ◽  
pp. 149-156 ◽  
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Ionization Potential ◽  
Wavelength Region ◽  
Rydberg Series ◽  
A Value ◽  
Ionization Limit ◽  
The Eu

The absorption spectrum of europium has been studied at high resolution in the wavelength region between 2200 and 2100 Å. Two Rydberg series were found converging towards the 9 S 4 and 7 S 3 levels of the configuration 4f 7 6s in Eu II. The first series is perturbed near the series limit and the second shows strong autoionization features. A value of 45734.9 ± 0.2 cm -1 is deduced for the first ionization limit.

THE ABSORPTION SPECTRUM OF 35Cl2 FROM 4780 TO 6000 Å

1963 ◽  
Vol 41 (7) ◽  
pp. 1174-1192 ◽  
Author(s):  
A. E. Douglas ◽  
Chr. Kn. Møller ◽  
B. P. Stoicheff
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Ground State ◽  
Dissociation Limit ◽  
Complex Spectrum ◽  
Absorption Bands ◽  
Isotopic Species ◽  
Concave Grating

The discrete absorption bands of gaseous chlorine which lie between 6000 Å and the dissociation limit, near 4780 Å, have been photographed at high resolution with a 10-meter concave-grating spectrograph. This complex spectrum has been simplified by the use of the separated isotopic species 35Cl2 and by cooling the cell. An analysis of all the strong bands has been achieved. The principal constants of the ground state are Be = 0.24407, α = 0.00153, ωe = 559.71, ωexe = 2.70, [Formula: see text], and re = 1.9878 Å.

The Absorption Spectrum of D2 from 1100 to 840 Å

1974 ◽  
Vol 52 (12) ◽  
pp. 1110-1136 ◽  
Author(s):  
I. Dabrowski ◽  
G. Herzberg
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Detailed Comparison ◽  
Electronic Energy ◽  
Dissociation Limit ◽  
Convergence Error ◽  
Vibrational Levels ◽  
Vibrational Constants

The absorption spectrum of D2 has been studied in absorption at high resolution (0.254 Å/mm) in the region 1100 to 840 Å. The three band systems B1Σu+ ← X1Σg+ (Lyman bands), B′ 1Σu+ ← X1Σg+ and C1Πu ← X1Σg (Werner bands) have been measured right up to the dissociation limit. New improved values of the rotational and vibrational constants in the three upper states have been derived. By comparing the electronic energy differences Tc thus obtained with the corresponding values for H2 fairly precise values for the electronic isotope shifts for the B–X and C–X systems have been determined (+ 2.8 and −7.4 cm−1 respectively). In this connection two gaps in the knowledge of the absorption spectrum of H2 have been filled: the Lyman bands with ν′ = 5–16 and the Werner bands with ν′ = 0–4 (see Appendix). A detailed comparison is made of the observed vibrational levels and the observed Bν values of D2 with those derived from ab initio calculations based on the Kotos and Wolniewicz' potential functions. From the observed electronic isotope shift the adiabatic corrections can be estimated near the minimum. For the B state these estimates agree very well with the ab initio calculations. The remaining differences between observation and theory are partly due to lack of convergence of the Born–Oppenheimer calculation, partly to the neglect of nonadiabatic corrections. The convergence error near minimum is estimated to be 5.1 cm−1 for the B state and 1.2 cm−1 for the C state.

scholarly journals High Resolution Photoionization Spectrum of HBr Measured With Frequency Tripled Laser Radiation

1987 ◽  
Vol 7 (2-4) ◽  
pp. 129-139 ◽  
Author(s):  
Toshiaki Munakata ◽  
Tadahiko Mizukuki ◽  
Akira Misu ◽  
Motowo Tsukakoshi ◽  
Takahiro Kasuya
Keyword(s):  
Laser Radiation ◽  
High Resolution ◽  
Ultraviolet Radiation ◽  
Ground State ◽  
Vacuum Ultraviolet ◽  
Second Harmonic ◽  
Rydberg Series ◽  
Vacuum Ultraviolet Radiation ◽  
Ionization Limit ◽  
Photoionization Spectrum

The photoionization spectrum of HBr around the first ionization limit was measured at resolution of up to 5 x 10−4 nm. The ionizing vacuum ultraviolet radiation was generated by frequency tripling of the second harmonic output of a dye laser. Three sets of Rydberg series, each converging to the ground state (2Π3/2) of HBr+, were observed on the longer wavelength side of the ionization limit. By extrapolation of the Rydberg series, the ionization potential of HBr was determined to be 11.666 ± 0.001 eV.

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.

Absorption spectrum of the NO molecule. VIII. The heterogeneous (2Σ–2Π) interactions between excited states

1968 ◽  
Vol 46 (8) ◽  
pp. 987-1003 ◽  
Author(s):  
Ch. Jungen ◽  
E. Miescher
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Excited States ◽  
Rydberg State ◽  
Vacuum Ultraviolet ◽  
Principal Quantum Number ◽  
Rydberg States ◽  
Infrared Emission ◽  
Strong Interactions ◽  
Rydberg Series

Heterogeneous perturbations 2E+ ~ 2Π of largely different magnitudes are observed with high resolution in the vacuum-ultraviolet absorption and in the infrared emission spectrum of the NO molecule. The rotational interactions between 2Σ+ Rydberg states and levels of the B2Π non-Rydberg state are shown to be "configurationally forbidden", but produced by the configuration interaction between the non-Rydberg levels and 2Π Rydberg states. The latter together with the 2Σ+ Rydberg states form p complexes. In this way the interactions display the l uncoupling in the complexes; they can be evaluated theoretically and can be analyzed fully. The cases of the strong interactions D2Σ+(v = 3) ~ B2Π(v = 16)and D2Σ+(v = 5) ~ B2Π(v = 21) and of the weaker D2Σ+(v = 1) ~ B2Π(v = 11), all three observed as perturbations in ε bands crossing 3 bands, are discussed in detail. It is further shown that perturbations between γ bands and β bands as well as perturbations between analogous bands of higher principal quantum number are absent, and thus the assignment of the A2Σ+ and E2Σ+ states to the s Rydberg series is confirmed.

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.

ON THE ABSORPTION SPECTRUM OF H2O AND D2O IN THE VACUUM ULTRAVIOLET

1963 ◽  
Vol 41 (2) ◽  
pp. 209-219 ◽  
Author(s):  
J. W. C. Johns
Keyword(s):  
Absorption Spectrum ◽  
Water Vapor ◽  
High Resolution ◽  
Heavy Water ◽  
Vacuum Ultraviolet ◽  
Rydberg Series ◽  
Accuracy Of Measurement ◽  
Concave Grating

The spectra of normal and heavy water vapor have been observed under high resolution in the region 1220–1240 Å. One band of H2O and two bands of D2O have been measured and analyzed. The spectra were taken in the ninth order of a 35-ft concave-grating spectrograph and the accuracy of measurement of the sharper lines is estimated to be about ± 0.005 Å. The results of the analyses are summarized below.[Formula: see text]These bands have been assigned as belonging to the first member of one of the two np Rydberg series.

The 7500 to 4500 Å absorption system of the free HCO radical

1955 ◽  
Vol 233 (1192) ◽  
pp. 34-54 ◽  
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Flash Photolysis ◽  
Lower State ◽  
Absorption System ◽  
Molecular Plane ◽  
Bending Mode ◽  
Vibrational Levels ◽  
Other Substances ◽  
Low Dispersion

A fairly extensive absorption spectrum o f the free HCO radical produced by flash photolysis of acetaldehyde and other substances has been investigated with long absorbing paths and under high resolution. The corresponding DCO spectrum has also been studied. The absorption spectrum consists of simple bands with P, Q and R branches. It is shown that the molecule is linear in the upper state, but bent in the lower state with an angle of about 120° and a CO bond length of approximately 1.20 Å. Rotational constants of HCO and DCO in both upper and lower states have been derived. Various arguments based on the high-resolution measurements lead to the conclusion that the main progression of bands corresponds to transitions to the vibrational levels of the upper state with even v' 2 (the vibrational quantum number of the bending mode). This conclusion is confirmed by the observation under low dispersion of some of the intermediate bands with odd v’ 2 which are diffuse and therefore not easily recognizable under high resolution. Apparently all levels of the upper state with l≠0 are predissociated. The type of the electronic transition is shown to be 2 Σ+ ← 2 A”, that is, the transition moment is perpendicular to the molecular plane. The lower state cannot arise from normal CO and H.

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