Emission Spectrum of the PO Molecule. Part II.2Σ–2Σ Transitions

1971 ◽  
Vol 49 (24) ◽  
pp. 3180-3200 ◽  
Author(s):  
R. D. Verma ◽  
M. N. Dixit ◽  
S. S. Jois ◽  
S. Nagaraj ◽  
S. R. Singhal
Keyword(s):  
Emission Spectrum ◽  
Ionization Potential ◽  
Dissociation Energy ◽  
Ground State ◽  
Rydberg States ◽  
Electronic States ◽  
Electronic Transitions ◽  
A Value ◽  
Upper Limit ◽  
First Ionization Potential

Rotational structure of emission bands of the PO molecule in the region 5300–3800 Å is analyzed. The spectrum is attributed to 5 electronic transitions A2Σ+–B2Σ+, F2Σ+–B2Σ+, G2Σ+–B2Σ+, H2Σ+–B2Σ+, and I2Σ+–B2Σ+, where F, G, H, and I are the new electronic states and A and B are the upper states of the well-known γ and β bands respectively. Practically all the new 2Σ states are found to be perturbed. A qualitative account of these perturbations together with a deperturbation of certain levels is given. A number of cases of predissociation are also observed. This predissociation is attributed to the presence of 4Πi, and A′2Σ+ states, which dissociate to the ground state atomic products. From this an upper limit of the dissociation energy of the ground state of PO is determined to be D0 = 49 536 cm−1. The A, D, E, G, H, and I states of this molecule are assigned as Rydberg states corresponding to the σ4s, π4p, δ3d, σ4p, σ3d, and σ5s orbitals, respectively. From them a value of 67 570 cm−1 is evaluated for the first ionization potential of PO. All the electronic states established for this molecule are described in terms of electron configurations.

Rydberg series and autoionization resonances in the Y I absorption spectrum

1973 ◽  
Vol 333 (1592) ◽  
pp. 17-24 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Ionization Potential ◽  
Excited States ◽  
Spectral Range ◽  
Ground State ◽  
Rydberg Series ◽  
A Value ◽  
Doublet Ground State ◽  
Ionization Limit ◽  
First Ionization Potential

The absorption spectrum of yttrium vapour has been photographed in the spectral range 1650 to 2250 À, with a 10 m spectrograph. Series of autoionization resonances, which converge on excited states of the Y + ion have been identified, as combinations with the doublet ground-state of Y I , 5s 2 4d 2 D 3/2 , 5/2 . Although the lines of these series show broadened and often asymmetrical profiles, the lines are sufficiently well defined to fix a value for the first ionization potential of Y I , which differs from the previously accepted value by approximately 2500 cm -1 . In addition, approximately 400 new Y I lines, which involve excited levels below the first ionization limit of Y I , namely 4s 2 1 S o , have been found. The majority of these are unclassifiable at present but, the value for the first ionization-potential being known from the resonances above-mentioned, two series of the character 5s 2 4d 2 D 3/2 , 5/2 -5s 2 nf 2 F o have been identified. In addition to the identifications of series, 152 new lines below the 5s 2 1 S o limit identify 76 new levels of Y I , of odd parity.

The electronic emission spectrum of triatomic hydrogen. I. Parallel bands of H3 and D3 near 5600 and 6025 Å

1980 ◽  
Vol 58 (8) ◽  
pp. 1238-1249 ◽  
Author(s):  
I. Dabrowski ◽  
G. Herzberg
Keyword(s):  
Interstellar Medium ◽  
Emission Spectrum ◽  
Detailed Analysis ◽  
Ground State ◽  
Emission Band ◽  
Rydberg States ◽  
Electronic States ◽  
Molecular Constants ◽  
Additional Band ◽  
Rydberg Electron

A spectrum of triatomic hydrogen and deuterium was first discovered by means of an emission band with diffuse rotational structure near 5600 Å. An additional band of similar but much better resolved structure was subsequently observed near 6025 Å. The detailed analysis of these two bands for both H3 and D3 is described in this paper. Both bands are [Formula: see text] bands of a symmetric top; their structure establishes beyond doubt that triatomic hydrogen has a D3h structure in its Rydberg states. The molecular constants in upper and lower states are close to those in the ground state of H3+ (or D3+) in accordance with the assumption that these states are Rydberg states in which a single electron moves around a H3+ or D3+ core. The predicted states of such a Rydberg electron in a field of D3h symmetry account very well for the observed electronic states, both those involved in the [Formula: see text] bands described here and those involved in the [Formula: see text] bands to be discussed in subsequent papers of this series. The lowest state of the Rydberg electron 2p2E′ is unstable and dissociates to H2 + H in their ground states. It is this state that causes predissociation in the two lower states 2s2A1′and 2p2A2″ of the two [Formula: see text] bands here under discussion. The predissociation of 2s2A1′ is vibronically allowed and fairly strong such that all lines have widths of about 7 cm−1 for D3 and 30 cm−1 for H3. The predissociation of the 2p2A2″ state is vibronically forbidden and occurs only on account of ro-vibronic interaction. H3+ ions are assumed to be present in the interstellar medium. When they recombine with electrons they must necessarily emit the spectra described in this series of papers.

Calculated Rydberg States of the PO Molecule

1972 ◽  
Vol 50 (7) ◽  
pp. 692-699 ◽  
Author(s):  
F. Ackermann ◽  
H. Lefebvre-Brion ◽  
A. L. Roche
Keyword(s):  
Ionization Potential ◽  
Ground State ◽  
Valence State ◽  
Rydberg States ◽  
Electron Excitation ◽  
The Other ◽  
Molecular Ion ◽  
A Value ◽  
Good For ◽  
Lcao Mo

The Rydberg States of the PO molecule, converging to the ground state of the PO+ ion, are calculated using the LCAO–MO SCF orbitals of the molecular ion core. An adjustment between the observed and calculated values for the energy of the first Rydberg A2Σ+ state gives a value of about 66 400 cm−1 for the ionization potential of PO. The agreement between the experimental and calculated values is very good for the other observed Rydberg states. In the 5300–3800 Å region, no more than four 2Σ+ Rydberg states are expected, which supports the "deperturbation" procedure carried out by Verma. A comparison is made between the p, d, and ƒ complexes in PO and NO. The B2Σ+ state appears to be a valence state corresponding to the electron excitation from an antibonding (vπ)* orbital to a weakly antibonding (uσ)* orbital.

Rotational Structure in Some Higher Excited States of the GeF Molecule

1974 ◽  
Vol 52 (15) ◽  
pp. 1458-1475 ◽  
Author(s):  
R. W. Martin ◽  
A. J. Merer
Keyword(s):  
Emission Spectrum ◽  
Excited States ◽  
Ground State ◽  
Valence State ◽  
Rydberg States ◽  
The Other ◽  
Electronic Transitions ◽  
Lower State ◽  
High Dispersion ◽  
Higher Excited States

The weaker electronic transitions in the region 2000–9000 Å in the emission spectrum of GeF have been photographed at high dispersion; three new transitions with the A2Σ+ state as lower state have been discovered, and the various systems near 2100 and 8600 Å have been reassigned. The spectra have been explained in terms of six excited states lying between 40 000 and 50 000 cm−1 above the ground state, and representative bands involving all six have been analyzed rotationally. Five of these excited states are Rydberg states (5pσ, 5pπ, 4dπ, 4dδ, and 6sσ), and the other is the σπ22Δ valence state; this latter interacts strongly with the 4dδ 2Δ state.

Electronic spectrum of the BF molecule

1970 ◽  
Vol 48 (4) ◽  
pp. 432-452 ◽  
Author(s):  
R. B. Caton ◽  
A. E. Douglas
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Ionization Potential ◽  
Electronic Spectrum ◽  
Excited States ◽  
Electronic Absorption ◽  
Rydberg States ◽  
Electronic States ◽  
Rydberg Series ◽  
Absorption And Emission

The electronic absorption and emission spectrum of BF has been photographed at high resolution from 900 to 11 000 Å. In this work, many new electronic states have been found and corrections have been made to earlier work. The ionization potential has been determined to be between 89 635 and 89 680 cm−1, with the most probable value being 89 650 cm−1. Tables of the vibrational and rotational constants of all the known states of BF are presented. All but two of the excited states of BF have been classified as Rydberg states and have been assigned to Rydberg series. The interactions between the various Rydberg states are discussed.

The absorption spectrum of diatomic phosphorus between 1370 and 600 Å

1975 ◽  
Vol 342 (1628) ◽  
pp. 93-111 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Ionization Potential ◽  
Dissociation Energy ◽  
Ground State ◽  
Molecular Orbitals ◽  
The Other ◽  
Ultraviolet Absorption Spectrum ◽  
Rydberg Series ◽  
Far Ultraviolet ◽  
First Ionization Potential

Nine Rydberg series have been observed in the far ultraviolet absorption spectrum of P 2 . Four of these converge to the.(5σ g ) 2 (2π u ) 3 , 2II u (inv.) state of the ion which is established as being the ground state; four to the low-lying ...(5σ g ) (2π u ) 4 , A 2 Ʃ g + state and one to a newly identified (5σ g ) (2π u )3 2πg, F 2 Ʃ + u state. The first ionization potential is found to be 85 229 ± 15 cm-1 (10.567 ± 0.002eV), which is the limit corresponding to the upper component (2II1/2 ) of the inverted X 2II u state. The other limits are observed at 87 179 + 2cm -1 (A 2 Ʃ + g ) and 125 225 ± 10cm -1 (F 2 Ʃ + u ). The series have been interpreted in terms of molecular orbitals and are found to involve excitation of n sσ g , n dσ g , n dπ g and n dδ g for the X 2 II u core; n pπ u , n fσ u , and n fπ u for the A 2 Ʃ + g core and for the A 2 Ʃ + u core. The evaluation and identification of the series limits enables the relative positions of the states of P + 2 to be established. The dissociation energy of P + 2 is estimated to be 4.98 ± 0.01eV.

The 1650-1350 Å absorption spectrum of nitrogen dioxide

1962 ◽  
Vol 267 (1330) ◽  
pp. 395-407 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Nitrogen Dioxide ◽  
Ionization Potential ◽  
Ground State ◽  
Band System ◽  
Anharmonic Constant ◽  
Rydberg Transitions ◽  
First Ionization Potential

An analysis of the 1650-1350 Å band system of nitrogen dioxide has been carried out. A pattern of band spacings and intensities is found that is complex but regular. It is shown that this pattern is qualitatively, and to a large extent quantitatively, just what would be expected for a transition in which the shape of the molecule changes from bent to linear. The transition is a parallel one and the upper state has 2 Σ + u symmetry. The symmetrical stretching frequency is increased from its ground-state value to ca. 1420 cm -1 in the upper state. The upper-state bending frequency is ca. 600 cm -1 . The N — O length is decreased from its groundstate value, probably to 1·1(3) Å. The upper state resembles closely the ground state of NO + 2 . The transition is to be classed as one of the Rydberg transitions leading to the first ionization potential of NO 2 ; and the orbital to which the odd electron is transferred in the transition is (pσ) in type. The anharmonic constant g 22 for the linear upper state is found to be 2·(3) cm -1 . Other Rydberg transitions may well be present in the region, but have not been definitely identified.

Bonding and electronic states of boron in silicon nanowires characterized by an infrared synchrotron radiation beam

Nanoscale ◽  
2015 ◽  
Vol 7 (16) ◽  
pp. 7246-7251 ◽  
Author(s):  
N. Fukata ◽  
W. Jevasuwan ◽  
Y. Ikemoto ◽  
T. Moriwaki
Keyword(s):  
Synchrotron Radiation ◽  
Excited States ◽  
Silicon Nanowires ◽  
Ground State ◽  
Electronic States ◽  
Electronic Transitions ◽  
Synchrotron Radiation Beam ◽  
Radiation Beam ◽  
Acceptor Atom ◽  
Ft Ir

The first report of B local vibrational peaks and electronic transitions of a bound hole from the ground state of a B acceptor atom to excited states by means of micro-FT-IR measurements using an IR-SR beam.

scholarly journals The absorption spectra of hexatriene and divinyl acetylene in the vacuum ultra-violet

1946 ◽  
Vol 185 (1001) ◽  
pp. 182-191 ◽  
Keyword(s):  
Double Bond ◽  
Ionization Potential ◽  
Absorption Spectra ◽  
Wave Length ◽  
Ultra Violet ◽  
Ionization Potentials ◽  
A Value ◽  
Integral Graphs ◽  
First Ionization Potential ◽  
Vacuum Ultra Violet

The absorption spectra of hexatriene and divinyl acetylene have been investigated in the region 2700-1200 A. In both molecules the longest wave-length regions of absorption are the strongest and these are interpreted as N → V 1 intravalence shell transitions. The spectra appear to be consistent with a value of about 8·2 V for the first ionization potential of hexatriene. Calculations based oh certain features of the spectra give reasonable values for the double-bond resonance integral. Graphs are given which enable the first regions of absorption and the ionization potentials of the higher polyenes to be predicted.

The emission spectrum of ReO between 375 and 875 nm: A classification based on rotational analysis and Re16O/Re18O isotope shifts

1984 ◽  
Vol 62 (12) ◽  
pp. 1524-1537 ◽  
Author(s):  
Walter J. Balfour ◽  
Ram. S. Ram
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Electronic States ◽  
Electronic Transitions ◽  
Lower State ◽  
Rotational Analysis ◽  
Isotope Shifts ◽  
Isotopic Shifts

The emission spectrum of the ReO molecule has been photographed under high resolution between 375 and 875 nm. In addition to the 711.9 and 404.5 nm systems previously studied a large number of new electronic transitions have been classified on the basis of Re16O/Re18O isotopic shifts. The rotational structures of 18 bands of Re16O and 1 band of Re18O have been analyzed. Two low-lying electronic states in addition to the known common lower state of the 711.9 and 404.5 nm systems have been identified.

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