Vibrational dependence of the rotational, spin-orbit splitting, and lambda-doubling parameters in the C″5Πui state of N2 This article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.

2009 ◽  
Vol 87 (5) ◽  
pp. 601-606 ◽  
Author(s):  
O. Pirali ◽  
D. W. Tokaryk ◽  
M. Vervloet

We have recorded the high-resolution emission spectrum of the Herman infrared band (C″5Πui–A′5Σ g+ ) system of N2 in the 8000–15000 cm–1 range from an experimental set-up coupling a corona discharge with a supersonic expansion. The analysis of four new bands has permitted us to determine spectroscopic parameters of the v′ = 0 and v′ = 1 vibrational levels of the C″5Πui state and to study the vibrational dependence of the molecular parameters over the range v′ = 0 to v′ = 4. In particular, the values of the spin-orbit coupling and the Λ–doubling parameters are discussed.

The spin-orbit coupling terms in the molecular electronic Hamiltonian have important, spectroscopically observable, effects. In states possessing an orbital degeneracy (e.g. II states of diatomic molecules) they produce a first-order splitting of the various multiplet levels; and in states which are degenerate in spin only the y give second-order effects embodied in a n effective g tensor. Owing to the complexity of the spin-orbit operators, such effects are usually discussed using simple approximate form s and semi-empirical wave-functions. In this paper, the complete operators are employed in ab initio calculations of (i) the spin-orb it splitting of the 2 II ground states of NO and CH, and (ii) the g tensors of CN and NO 2 . The results are in good agreement with experiment. Detailed analysis of the calculations indicates a firm basis for semi-empirical procedures which could easily be applied to larger molecules. The evaluation of new integrals, involving the spin-orbit operators, is discussed in an appendix.


2018 ◽  
Vol 32 (05) ◽  
pp. 1850055 ◽  
Author(s):  
Ranber Singh

The spin–orbit splitting (E[Formula: see text]) of valence band maximum at the [Formula: see text] point is significantly smaller in 2D planner honeycomb structures of graphene, silicene, germanene and BN than that in the corresponding 3D bulk counterparts. For 2D planner honeycomb structure of SiC, it is almost same as that for 3D bulk cubic SiC. The bandgap which opens at the K and K[Formula: see text] points due to spin–orbit coupling (SOC) is very small in flat honeycomb structures of graphene and silicene, while in germanene it is about 2 meV. The buckling in these structures of graphene, silicene and germanene increases the bandgap opened at the K and K[Formula: see text] points due to SOC quadratically, while the E[Formula: see text] of valence band maximum at the [Formula: see text] point decreases quadratically with an increase in the magnitude of buckling.


1969 ◽  
Vol 47 (23) ◽  
pp. 2727-2730 ◽  
Author(s):  
H. Lefebvre-Brion ◽  
N. Bessis

The origin of the splitting of the 2Δ states arising from the σπ2 configuration is studied. For light diatomic molecules, the splitting is shown to arise from the spin–other–orbit interaction which gives a small negative value for the spin–orbit coupling constant A. Non-empirical calculations of A for the 2Δ states of the CH, NH+, and NO molecules are in good agreement with experiment. In heavier molecules, the spin–other–orbit interaction becomes negligible and the second-order spin–orbit effect is dominant.


1986 ◽  
Vol 90 ◽  
Author(s):  
T. Nguyen Duy ◽  
A. Durand ◽  
J. L. Lyot

ABSTRACTHigh gap Hg1−xCdxTe (MCT) crystal is grown by a solvent method using a travelling heater zone. The use of the solvent zone permits a low temperature and low mercury pressure growth of MCT in a large composition range. In the Cadmium rich alloy range the MCT material exhibits a large spin orbit coupling leading to a resonance at Eg = ΔO. Due to this particular resonance effect the ionization coefficient of hole is higher than that of the electron, resulting in a low exess noise factor in the avalanche photodiodes whose bandgap energy is close to the spin orbit splitting ΔO.


The spin-orbit splitting in orbitally degenerate systems with one open shell usually conforms to Hund’s third rule: that is, the splitting is regular for a less than half-filled shell, and inverted for a more than half-filled shell. The C 2 T 2 states of CF+4 and SiF+4 reported by Mason & Tuckett violate this expectation. We show below how this may occur in AX+4 ions where the dominant atomic spin-orbit coupling arises from motion around the X atoms.


Nanoscale ◽  
2021 ◽  
Author(s):  
Xilong Liang ◽  
Chengbing Qin ◽  
Yan Gao ◽  
Shuangping Han ◽  
Guofeng Zhang ◽  
...  

Monolayer transition metal dichalcogenides, manifesting strong spin-orbit coupling combined with broken inversion symmetry, lead to a coupling of spin and valley degrees of freedom. These unique features make them highly...


The tensor-operator and group-theoretical methods of Racah are used to examine the following contributions to the Hamiltonian of a rare-earth ion: ( a ) the Coulomb interaction between the electrons, ( b ) the spin-orbit coupling of the electrons, and ( c ) the term arising from the influence of an external electrostatic field such as occurs when the rare-earth ion is situated in a crystal lattice. With regard to ( a ), the positions of all the terms of the configurations f 2 , f 3 and f 4 , as well as all the terms of other configurations f n whose multiplicities are the highest or the highest but one, are tabulated on the basis of a hydrogenic 4 f wave function. The theory of ( b ) is developed, and the parameter λ defining the spin-orbit splitting of a term is given for all terms whose energies have been found, ( c ) is treated by similar techniques and the theory is related to the one at present in use. All the general methods are illustrated by examples.


1995 ◽  
Vol 50 (11) ◽  
pp. 1041-1044 ◽  
Author(s):  
J. Schiedt ◽  
R. Weinkauf

Abstract We could resolve the spin-orbit splitting of 160 ± 4 cm-1 in the 2II ground state of O2- anions by high resolution photodetachment photoelectron spectroscopy. The observed splitting is in good agreement with the theoretically derived value. Our directly measured electron affinity of O 2 is 450 ± 2 meV and deviates within experiment errors from previous values. kHz repetition rate was applied to avoid space charge and improve electron energy resolution in a time-of-flight electron energy analyzer.


1967 ◽  
Vol 22 (6) ◽  
pp. 945-954 ◽  
Author(s):  
Chr. Klixbüll Jørgensen ◽  
W. Preetz

The previous M.O. treatment of unsubstituted hexahalides has been modified, taking the results on Faraday effect obtained at the University of Virginia into account. The absorption spectra previously measured of the complexes (M=Os, Ir) trans-MCl4Br2— and trans-MCl2 Br4— are interpreted by a M.O. treatment for the symmetry D4h as electron transfer transitions, including a first-order relativistic (spin-orbit coupling) correction. The concept of holohedrized symmetry is sufficiently valid to allow a description of MCl5Br— and MClBr5— as if they were tetragonal with centre of inversion and ƒac-(or cis-)MCl3Br3— as if they were cubic. It is shown that the ligand-ligand antibonding effects have the same order of magnitude as the moderate difference in optical electronegativity between Cl- and Br-.


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