On the basis of the optical and dielectric investigations of [(CH3)2NH2]5Cd2CuCl11 solid solutions the existence of phase transitions at T1 = 175 K and T2 = 117.5 K was confirmed. Both phase transitions were found to be shifted toward lower temperatures with respect to the corresponding transitions in the “host” [(CH3)2NH2]5Cd3Cl11 crystals. It was found that the proton conductivity in [(CH3)2N...

Interplay between the vibronic and spin-orbit coupling in the ͑⌫ 8 + ⌫ 9 ͒ ϫ ͑g +2h͒ Jahn-Teller problem, where ⌫ 8 and ⌫ 9 are the quartet and sextet spin representation, and g and h denote the fourfold and fivefold degenerate vibrational modes in icosahedral symmetry, respectively, is studied. A 4d 9 or 5d 9 transition-metal ion in an icosahedral field may provide a realization of this system.

The Jahn-Teller and spin-orbit coupling in the ground states of the CF3O and CF3S radicals have been investigated experimentally by dispersed fluorescence spectroscopy. These spectra are analyzed using a theoretical model that simultaneously includes spin-orbit coupling and multimode Jahn-Teller, both linear and quadratic. We find that in each of these radicals a moderate linear Jahn-Teller eff...

Competing Jahn-Teller distortions combined with geometrical frustration give rise to a rich phase diagram as a function of x(Cu) and temperature in the spinel system Ni1xCuxCr2O4. The Jahn-Teller distortion of the end members acts in opposite ways with an elongation of the NiO4 tetrahedra resulting in a structural transition at TS1 = 317 K in NiCr2O4, but a flattening in the CuO4 tetrahedra at...

The multideterminental-DFT approach was performed in order to calculate the Jahn-Teller (JT) parameters for the JT active molecules. Within the harmonic approximation the JT distortion can be analysed as a linear combination of all totally symmetric normal modes in any of the low symmetry minimum energy conformation, which allows to calculate the Intrinsic Distortion Path (IDP), exactly from th...

Relations between the total β+ Gamow-Teller (GT+) strength and the E2 strength are further examined. It is found that in shell-model calculations for N =Z nuclei, in which changes in deformation are induced by varying the single-particle energies, the total GT+ or GT− strength decreases monotonically with increasing values of the B(E2) from the ground state to the first excited J π =2 + state. ...

Jahn-Teller (JT) electron-phonon coupling effects in the colossal magnetoresistance perovskite compounds La1−xAxMnO3 are investigated. Electronelectron correlations between two degenerate Mn eg orbitals are studied in the Gutzwiller approximation. The static JT distortion and antiadiabatic polaron effects are studied in a modified Lang-Firsov approximation. We find that (i) the electron or hole...

The 11B(3He, t), 11B(d, d), and 11B(p, p) reactions were measured at forward scattering angles including 0 to study the isovector and isoscalar spin-flip M1 strengths in 11B. The measured 11B(3He, t) cross sections were compared with the results of the distorted-wave impulseapproximation (DWIA) calculation, and the Gamow-Teller (GT) strengths for low-lying states in 11C were determined. The GT ...

In the well known Pöschl-Teller trigonometric potential well, a PT symmetric regularization x → x− i ε of the “impenetrable” end-point barriers is performed. This leads to the four different solvable generalizations of the model. As a byproduct, the scheme clarifies certain apparent paradoxes encountered in the classically forbidden coupling regime. PACS 03.65.Bz 03.65.Ca 03.65.Ge 02.60.Lj 11.3...