Vibronically induced Jahn–Teller progressions in the electronic spectrum of iridium hexafluoride

1968 ◽  
Vol 46 (15) ◽  
pp. 1721-1724 ◽  
Author(s):  
J. C. D. Brand ◽  
G. L. Goodman
Keyword(s):  
Electronic Spectrum ◽  
Excited States ◽  
Electric Dipole ◽  
Ground State ◽  
Electronic States ◽  
Electronic Transitions ◽  
Electrostatic Forces ◽  
First Approximation ◽  
Jahn Teller

The absorption of IrF6 vapor between 0.7 and 1.3 μ consists of three distinct electronic transitions connecting the Γ8g ground state with higher Γ6g, Γ8g, and Γ7g states of the (5d f2g)3 configuration. In first approximation, Jahn–Teller forces vanish in the two Γ8g states, while the Γ6g and Γ7g states involve Kramers magnetic degeneracy, which cannot be split by electrostatic forces. Accordingly, no splittings of the ν2(eg) or ν5(f2g) excited states are observed in these spectra, but short progressions in ν5 do appear in the electric-dipole-allowed, vibronic parts of these transitions. These progressions are considered to show that Jahn–Teller anharmonicity can be induced by admixtures of odd-parity, orbitally degenerate electronic states, i.e. by the same mechanism through which these transitions derive their electric-dipole intensity.

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.

Upconversion Luminescence Study of Er3+ in Gadolinium-Calcium- Silicoborate Glasses

2013 ◽  
Vol 770 ◽  
pp. 249-253 ◽  
Author(s):  
Jakrapong Kaewkhao ◽  
Hong Joo Kim ◽  
Smit Insiripong ◽  
Natthakridta Chanthima ◽  
Siriprapa Kaewjaeng ◽  
...  
Keyword(s):  
Excited States ◽  
Ground State ◽  
Upconversion Luminescence ◽  
Optical Devices ◽  
Electronic Transitions ◽  
Potential Candidate ◽  
Melt Quenching ◽  
Absorption Bands ◽  
Green Is ◽  
Glass Series

The new glass series were prepared in compositions 25Gd2O3-10CaO-10SiO2-(55-x) B2O3-xEr2O3 (where x is 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) by normal melt-quenching technique at the melting temperature of 1,400 °C. The optical spectra were measured and shown absorption bands were assigned to appropriate f-f electronic transitions of Er3+ ions from the 4I15/2 ground state to the following excited states: 4G11/2, 2H9/2, 4F5/2, 4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I9/2 and 4I11/2. Single peak from upconversion luminescence was observed at 531 nm (green) is assigned to the 2H11/24I15/2. In this work, the strongest peak at 2.0 % mol of Er2O3 was observed. In this work, suggests that the Er3+ ion in gadolinium calcium silicoborate glasses possibly considered as a potential candidate for applications in upconversion-based optical devices.

Electronic spectrum of H2O+

1976 ◽  
Vol 54 (20) ◽  
pp. 2028-2049 ◽  
Author(s):  
H. Lew
Keyword(s):  
Emission Spectrum ◽  
Electronic Spectrum ◽  
Ground State ◽  
Energy Levels ◽  
Bond Distance ◽  
Electronic States ◽  
Wavelength Region ◽  
Astrophysical Interest ◽  
Vibrational Levels ◽  
Wave Numbers

Many bands of the [Formula: see text] electronic emission spectrum of H2O+, occurring in the wavelength region 4000–7500 Å, have been analyzed. These include bands that have been observed in the tails of comets. The wavelengths and wave numbers of all assigned lines are tabulated. Accurate rotational constants for the first three bending vibrational levels of the ground state are given, as well as energy levels in the upper and lower electronic states. The O—H bond distance and the H—O—H angle in the [Formula: see text] (0, 0, 0) level are found to be 0.9988 Å and 110.46° respectively. Some predicted microwave and infrared lines that may be of astrophysical interest are included.

scholarly journals Geometrical Reorganization of a Methane Cation upon a Sudden Ionization: An Isotope Effect in Electronic Non Equilibrium Quantum Dynamics

2021 ◽  
Author(s):  
Cayo Gonçalves ◽  
Raphael D. Levine ◽  
Francoise Remacle
Keyword(s):  
Isotope Effect ◽  
Ground State ◽  
Quantum Dynamics ◽  
High Harmonic ◽  
Electronic States ◽  
Structural Rearrangement ◽  
Experimental Measurements ◽  
Strongly Coupled ◽  
Jahn Teller ◽  
Electronic Coherence

<p>An ultrafast structural, Jahn-Teller (JT) driven, electronic coherence mediated quantum dynamics in the CH<sub>4</sub><sup>+</sup> and CD<sub>4</sub><sup>+ </sup>cations that follows a sudden ionization by an XUV attopulse, exhibits a strong isotope effect. The JT effect makes the methane cation unstable in the T<sub>d</sub> geometry of the neutral. Upon the sudden ionization the cation is produced in a coherent superposition of three electronic states that are strongly coupled. On the ground state of the cation the few femtosecond structural rearrangement leads first to a geometrically less distorted D<sub>2d</sub> minimum followed by a reorganization to a shallow C<sub>2v</sub> minimum. The dynamics is computed for an ensemble of 8000 ions randomly oriented with respect to the polarization of the XUV pulse. The ratio, about 3, of the CD<sub>4</sub><sup>+</sup> and CH<sub>4</sub><sup>+</sup><sub> </sub>autocorrelation functions, is in agreement with experimental measurements of the high harmonic spectra. The high value of the ratio is attributed to the faster electronic coherence dynamics in CH<sub>4</sub><sup>+</sup>. </p>

Optical absorption spectra of octahedrally bonded Fe3+ in vesuvianite

1968 ◽  
Vol 5 (1) ◽  
pp. 89-92 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Optical Absorption ◽  
Energy Range ◽  
Absorption Spectra ◽  
Excited States ◽  
Ground State ◽  
Electronic Transitions ◽  
Optical Absorption Spectra ◽  
Sharp Band ◽  
Individual Bands ◽  
The Individual

The optical absorption spectra of green vesuvianite crystals from Lowell County, Vermont, are reported in the energy range 12 000 cm−1 to 30 000 cm−1. The principal absorptions have been attributed to octahedrally bonded Fe3+ and the individual bands have been assigned to spin-forbidden electronic transitions from the 6A1 ground state to excited states in Fe3+. In particular, the 6A1 → 4A14E(G) transition is marked by a relatively sharp band at 21 600 cm−1.

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.

Photoneutrons from 19F

1976 ◽  
Vol 54 (11) ◽  
pp. 1178-1189 ◽  
Author(s):  
N. K. Sherman ◽  
K. H. Lokan ◽  
R. W. Gellie
Keyword(s):  
Excited States ◽  
Cross Section ◽  
Electric Dipole ◽  
Ground State ◽  
Time Of Flight ◽  
Branching Ratios ◽  
Integrated Cross Section ◽  
Time Of Flight Method

The 19F(γ,n) reaction was studied by irradiating teflon with bremsstrahlung of energy increasing from 13 MeV to 21 MeV in 1 MeV steps. Photoneutron spectra were measured by the time-of-flight method. Excited states of 19F at 12.10, 12.38, 13.82, and 16.24 MeV were observed. The total integrated cross section between 11.9 and 17.9 MeV was found to be (14.4 ± 2.2) MeV mb. Branching ratios to the first group of excited states of 18F compared to the ground state were measured, along with resonance widths and approximate radiative widths. They are consistent with the interpretation that all four states arise from electric dipole d → f valence transitions, with the first two states having Jπ = 1/2−, and the second two having 3/2−.

THE ABSORPTION SPECTRUM OF CNC

1966 ◽  
Vol 44 (2) ◽  
pp. 353-372 ◽  
Author(s):  
A. J. Merer ◽  
D. N. Travis
Keyword(s):  
Absorption Spectrum ◽  
Bond Length ◽  
Ground State ◽  
Flash Photolysis ◽  
Electronic States ◽  
Electronic Transitions ◽  
Ultraviolet Absorption Spectrum ◽  
Rotational Analysis ◽  
Bending Vibrations ◽  
Show Evidence

The ultraviolet absorption spectrum of the free CNC radical has been discovered in the flash photolysis of diazoacetonitrile, HC(CN)N2. The identity of the radical has been proved from isotopic evidence, using 15N and 13C, together with rotational analysis of the bands. Rotational analyses have shown that the bands of CNC must be assigned to two electronic transitions, A2Δu–X 2Πg, and [Formula: see text]. The sequence bands in the bending vibrations, which are observed in both electronic transitions, show evidence of Renner–Teller interaction in both the degenerate electronic states: this interaction is extremely large in the X2Πg state. The principal constants (in cm−1) of the observed states of CNC are as follows:[Formula: see text]The C—N bond length in the ground state of CNC is found to be 1.245 Å.CNC is isomeric with CCN, whose spectrum has been reported previously; some interesting comparisons are made between the spectra of these two molecules.

The photoelectron spectrum of sulphur trioxide: Jahn-Teller distortion in SO + 3

1974 ◽  
Vol 336 (1606) ◽  
pp. 355-364 ◽  
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Photoelectron Spectrum ◽  
Electronic States ◽  
Teller Distortion ◽  
Definite Evidence ◽  
Spin Resonance ◽  
Jahn Teller ◽  
Sulphur Trioxide ◽  
Jahn Teller Distortion

The photoelectron spectrum of sulphur trioxide has been recorded and extensive fine structure resolved. In three bands of the spectrum there is evidence for Jahn-Teller distortion. This has been interpreted quantitatively using the model of Longuet-Higgins, Opik, Pryce & Sack (1958). It also provides definite evidence that the three bands correspond to degenerate electronic states of SO + 3 . Four ionization potentials were found with values 12.8, 13.8, 14.9 and 17.9 eV. In two cases approximate changes in the S—O bond length have been calculated from the experimental data. The order of the first three electronic states of SO + 3 is unexpected, the ground state being degenerate. This result is compared with other data from photoelectron, ultraviolet and electron spin resonance spectra of isoelectronic species.

Ultrafast dynamics in LMCT and intraconfigurational excited states in hexahaloiridates(iv), models for heavy transition metal complexes and building blocks of quantum correlated materials

2020 ◽  
Vol 22 (30) ◽  
pp. 17351-17364
Author(s):  
Darya S. Budkina ◽  
Firew T. Gemeda ◽  
Sergey M. Matveev ◽  
Alexander N. Tarnovsky
Keyword(s):  
Excited States ◽  
Transition Metal Complexes ◽  
Electronic States ◽  
Building Blocks ◽  
Ultrafast Dynamics ◽  
Relaxation Dynamics ◽  
Excited Electronic States ◽  
Ultrafast Relaxation ◽  
Jahn Teller ◽  
Jahn Teller Effect

Two heavy octahedral Ir(iv) halides in intraconfigurational and LMCT excited electronic states with ultrafast relaxation dynamics driven by the Jahn–Teller effect.

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