The Vacuum Ultraviolet Spectrum of Selenium Hydride I. Determination of the Ground State Spin-Orbit Coupling Constant

1978 ◽  
Vol 17 (6) ◽  
pp. 561-564 ◽  
Author(s):  
P Bollmark ◽  
B Lindgren ◽  
B Rydh ◽  
U Sassenberg
Author(s):  
E. Cicely Ridley

ABSTRACTSelf-consistent fields without exchange have been calculated for the ground state of Pr3+ and Tm3+. The spin-orbit coupling constant ζ(4f) is found to have the values 785 and 2742 cm−1 in Pr3+ and Tm3+, respectively. The corresponding values of are 29·4 and 77·5 Å−3. Values of the Slater integrals F2(4f, 4f), F4(4f, 4f) and F6(4f, 4f) are also given for each structure.


1971 ◽  
Vol 49 (15) ◽  
pp. 2033-2051 ◽  
Author(s):  
L. Harding ◽  
W. E. Jones ◽  
K. K. Yee ◽  
A. Jenouvrier ◽  
D. Daumont ◽  
...  

The vibrational and rotational analysis of 12 red degraded bands of N80Se, in the region 2800 to 3200 Å, is reported. These bands are attributed to two progressions, ν′ = 1 and ν′ = 2, of the subsystem C2Δ5/2–X2Π3/2 and to two progressions, ν′ = 0, of the system B2Σ–X2Π(a).Tables of molecular constants of the observed states are given. For the first time it has been possible to calculate the spin–orbit coupling constant, Aeff, of the ground state, X2Π(a).


The position of the F band peak is determined in additively coloured CaF 2 , SrF 2 and BaF 2 by the Faraday rotation method. However, in additively coloured crystals, the F band is normally overlaid by absorption due to higher F aggregate centres and a determination of the spin orbit coupling constant in the excited 2 P state of the F centre is not feasible since a precise knowledge of the F band optical density is required. It is found that trapped electron centres are produced by X-irradiation at 77 °K of undoped SrF 2 and BaF 2 crystals and hydrogen doped CaF 2 , SrF 2 and BaF 2 crystals and the spin orbit coupling is determined for these centres. Paramagnetic resonance measurements show (Bessent, Hayes, Hodby & Smith 1968) that the trapped electron centres are closely related to the normal F centres found in additively coloured crystals. Wavefunctions obtained from a point ion model (Bennett & Lidiard 1965) are used to calculate the spin orbit coupling for the 2 P state of the F centre in CaF 2 , SrF 2 and BaF 2 . For comparison with theory it is assumed that the spin orbit coupling for the irradiation induced trapped electron centres is not appreciably different from that for normal F centres and we obtain good agreement between theory and experiment.


1975 ◽  
Vol 53 (4) ◽  
pp. 420-423 ◽  
Author(s):  
H. R. Zaidi ◽  
R. D. Verma

Expressions are derived for the spin–orbit coupling constant, AvJ, for an isolated 2Π state of a diatomic molecule. These results are applied to the X2Π states of PO. Comparison with the available experimental results allows a determination of the first three derivatives of the coupling parameter at the equilibrium position. It is found that the second derivative gives the largest contribution, thus invalidating a common assumption of the existing theories.


1977 ◽  
Vol 55 (10) ◽  
pp. 937-942 ◽  
Author(s):  
A. F. Leung ◽  
Ying-Ming Poon

The absorption spectra of UCl5 single crystal were observed in the region between 0.6 and 2.4 μm at room, 77, and 4.2 K temperatures. Five pure electronic transitions were assigned at 11 665, 9772, 8950, 6643, and 4300 cm−1. The energy levels associated with these transitions were identified as the splittings of the 5f1 ground configuration under the influence of the spin–orbit coupling and a crystal field of C2v symmetry. The number of crystal field parameters was reduced by assuming the point-charge model where the positions of the ions were determined by X-ray crystallography. Then, the crystal field parameters and the spin–orbit coupling constant were calculated to be [Formula: see text],[Formula: see text], [Formula: see text], and ξ = 1760 cm−1. The vibronic analysis showed that the 90, 200, and 320 cm−1 modes were similar to the T2u(v6), T1u(v4), and T1u(v3) of an UCl6− octahedron, respectively.


1972 ◽  
Vol 50 (10) ◽  
pp. 1468-1471 ◽  
Author(s):  
Alan D. Westland

An expression for the magnetic susceptibility of octahedral d1 complexes is derived exactly in terms of an orbital reduction factor k taking into account the presence of the formal 2E excited state. Sample calculations show that the improved expression gives results for susceptibility which are lower at times by several percent from those given by previous expressions. The results given by Figgis using Kotani's method are adequately precise when the spin–orbit coupling constant is no larger than ~0.1 Dq.


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