scholarly journals Терагерцовая спектроскопия магнитоэлектрика HoAl-=SUB=-3-=/SUB=-(BO-=SUB=-3-=/SUB=-)-=SUB=-4-=/SUB=-

2022 ◽  
Vol 130 (1) ◽  
pp. 59
Author(s):  
А.М. Кузьменко ◽  
В.Ю. Иванов ◽  
А.Ю. Тихановский ◽  
А.Г. Пименов ◽  
А.М. Шуваев ◽  
...  

Experimental and theoretical study of submillimeter (terahertz) spectroscopic and magnetic properties of the rare-earth aluminum borate HoAl3(BO3)4 were performed at temperatures 3–300 K. In the transmittance spectra a number of resonance lines were detected at frequencies 2–35 cm–1 for different radiation polarizations. These modes were identified as transitions between the lower levels of the ground multiplet of the Ho3+ ion split by the crystal field, including both transitions from the ground state to the excited ones and transitions between the excited states. The established excitation conditions of the observed modes and the simulation of the spectra made it possible to separate the magnetic and electric dipole transitions and to determine the energies of the corresponding states, their symmetry, and the matrix elements of the transitions. Low-frequency lines that do not fit into the established picture of the electron states of Ho3+ were also found; these lines, apparently, correspond to the ions with the distorted by defects local symmetry of the crystal field.

In recent work on the rare-earth double nitrates, it has been found necessary to extend the theory of crystal fields to cases of C 3 ­v ­ symmetry. Operator equivalences are given for the potentials V 3 4 and V 3 6' , defined by ∑ z ( x 3 - 3 xy 2 ) and Ʃ(11 z 3 - 3 zr 2 ) ( x 3 - 3 xy 2 ) respectively, and their matrix elements tabulated over a range of J (the total angular momentum) which includes the ground states of all the rare-earth ions. Operator-equivalent factors are given for certain excited levels in praseodymium and neodymium ions, and a method is described for finding these factors for levels which derive from terms that occur twice in a configuration of the form f n . The dependence on J and J z of the matrix elements of the crystal-field interaction between different J levels is given for the components of a crystal field with C 3 v symmetry.


1976 ◽  
Vol 29 (3) ◽  
pp. 177 ◽  
Author(s):  
DJ Newman

It is shown that the matrix elements of the tensor operators describing a new type of crystal field can be calculated using the properties of the spin ~ quasi-spin transformation. The relationship of this field to electron correlation in open shells is clarified, and its contribution to the ground state splittings of S-state ions is discussed


2018 ◽  
Vol 178 ◽  
pp. 02030
Author(s):  
Swati Modi

A systematic study of ground state spectrum with the triaxial deformation γ for odd-A Iodine isotopes 109−117I is carried out with the nonadiabatic quasiparticle approach. The rotation-particle coupling is accomplished microscopically such that the matrix elements of a particle-plus-rotor system are written in terms of the rotor energies. The 5/2+ state is confirmed as ground state for odd-A 111−117I and also coming out as lowest in energy for 109I.


2003 ◽  
Vol 217 (3) ◽  
pp. 255-264 ◽  
Author(s):  
M. Diehr ◽  
G. Chambaud ◽  
H.-J. Werner

AbstractLarge scale MRCI calculations have been performed to study the electronic ground state and low-lying excited states of the NCS molecule and its isomers. The isomer CNS is found to be stable and linear. It lies 1.29 eV higher in energy than NCS, while CSN has a much higher energy and is unstable. The dissociation energy of the NCS isomer has been calculated to be 4.25 eV. The isomerization paths between the 2Π ground states of both isomers have been mapped by CASSCF and MRCI calculations. The barriers for the NCS → CNS isomerization in 2A′ and 2A″ symmetry have cyclic forms and the barrier heights have been calculated to be 2.71 eV and 2.44 eV, respectively (MRCI). For both isomers, the collinear dissociation paths to the (diatomic + atom) fragments have been investigated by CASSCF calculations. Spectroscopic data are given for the X2Π ground state and for the A2Σ+ state of CNS. The results are compared with the valence isoelectronic system NCO.


2006 ◽  
Vol 15 (08) ◽  
pp. 1723-1733 ◽  
Author(s):  
FENG PAN ◽  
TAO WANG ◽  
Y.-S. HUO ◽  
J. P. DRAAYER

Quantum phase transitional patterns in the whole parameter space of the consistent-Q Hamiltonian in the Interacting Boson Model are studied based on an implemented Fortran code for numerical computation of the matrix elements in the SU (3) Draayer-Akiyama basis. Results with respect to both ground and some excited states of the model Hamiltonian are discussed. Quantum phase transitional behavior under a variety of parameter situations is shown. It is found that transitional behavior of excited states is more complicated. Pt isotopes are taken as examples in illustrating the prolate-oblate shape phase transition.


2011 ◽  
Vol 233-235 ◽  
pp. 2871-2874
Author(s):  
Zhi Xong Huang ◽  
Gang Qin ◽  
Ming Zhang ◽  
Yan Qin ◽  
Lian Meng Zhang

The excited states of methyl methacrylate(MMA) were calculated by CIS method, MMA molecules on the ground and excited states of molecular structures were optimized. The HOMO and LUMO molecular orbitals of MMA molecule are given in the ground state and excited state . The results show that: MMA is excited, the molecular orbital from 27 → 28, the excitation energy is 1.4310eV, Carbon-carbon(C=C)double bonds break.


1990 ◽  
Vol 05 (19) ◽  
pp. 1477-1483 ◽  
Author(s):  
K. TERASAKI ◽  
S. ONEDA

It is argued that the asymptotic behavior of the matrix elements of Hw involving on-mass-shell ground-state mesons with infinite momenta, which were instrumental in explaining the |ΔI|=1/2 rule in the K→ππ decays, actually implies [Formula: see text]. The long distance effects (contributions of PS and vector meson poles and ππ intermediate states) may reproduce the observed KL−Ks mass difference, consistent with the |ΔI|=1/2 rule. Its estimate is however sensitive to the η-η′-… mixing.


1975 ◽  
Vol 53 (21) ◽  
pp. 2421-2427 ◽  
Author(s):  
Jacek Karwowski ◽  
K. M. S. Saxena ◽  
Serafin Fraga

A new formulation for the evaluation of the matrix elements of the spin-own orbit interaction in many-electron atoms has been applied to the evaluation of the interaction matrices for pN, dN, and fN configurations, using functions that are simultaneous eigenfunctions of the operators J2, L2,S2, and.Jz; the complete results are available as indicated in the text. Using this formulation, the fine structure intervals for the ground states of the neutral atoms and the first three positive ions of the elements of the three transition series have been calculated within the framework of the monoconfigurational approximation, including the electrostatic and spin-own orbit interaction between the states arising from the configuration under consideration. In each case, the spin–orbit parameter and the set of Slater–Condon integrals, obtained from the numerical Hartree–Fock function for the ground state, were used.


2010 ◽  
Vol 25 (21n23) ◽  
pp. 1919-1922
Author(s):  
M. GRASSO ◽  
D. GAMBACURTA ◽  
F. CATARA

Second RPA calculations with a Skyrme force are performed to describe both high- and low-lying excited states in 16 O . The coupling between 1 particle-1 hole and 2 particle-2 hole as well as that between 2 particle-2 hole configurations are fully taken into account and the residual interaction is never neglected. For the rearrangement terms in the matrix elements beyond standard RPA two approximations are employed: they are either neglected or evaluated with the RPA procedure. A several-MeV shift of the strength distribution to lower energies is systematically found with respect to RPA distributions. A better description of the excitation energies of the low-lying 0+ and 2+ states is obtained with second RPA with respect to RPA.


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