The Jahn–Teller effect in the lower electronic states of benzene cation. II. Vibrational analysis and coupling constants of the B̃ 2E2g state

2002 ◽  
Vol 117 (22) ◽  
pp. 10001-10007 ◽  
Author(s):  
Philip M. Johnson
Keyword(s):  
Vibrational Analysis ◽  
Electronic States ◽  
Coupling Constants ◽  
Teller Effect ◽  
Jahn Teller ◽  
Jahn Teller Effect

Cooperative Pseudo Jahn-Teller Effect as Microscopic Mechanism of (OMT)-(LTT) Structural Phase Transition in La2−xBaxCuO4Superconductors

1992 ◽  
Vol 291 ◽  
Author(s):  
Michael D. Kaplan
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Electronic States ◽  
Teller Effect ◽  
Excited Electronic States ◽  
Microscopic Mechanism ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Local Distortions

ABSTRACTA microscopic mechanism for the structural phase transition from the orthorhombic mediate temperature (OMT) phase into the low temperature tetragonal (LTT) one is suggested on the basis of the cooperative pseudo Jahn-Teller effect. The local distortions mixing the ground and the first excited electronic states are ordered antiferrodistortively and are connected in part, with the oxygen octahedra rotations around the [100] axis. The results are in agreement, with the neutron scattering experiments data.

scholarly journals The Jahn–Teller effect in the presence of partial isotopic substitution: the B̃1E′′ state of NH2D and NHD2

2015 ◽  
Vol 17 (21) ◽  
pp. 14145-14158 ◽  
Author(s):  
Ashim Kumar Saha ◽  
Gautam Sarma ◽  
Chung-Hsin Yang ◽  
Sebastiaan Y. T. van de Meerakker ◽  
David H. Parker ◽  
...  
Keyword(s):  
Force Field ◽  
Field Model ◽  
Electronic States ◽  
Teller Effect ◽  
Isotopic Substitution ◽  
Quadratic Force Field ◽  
Jahn Teller ◽  
Jahn Teller Effect

A simple linear and quadratic force field model for the lifting of the degeneracy on asymmetric isotopic substitution in degenerate electronic states subject to a weak Jahn–Teller effect.

Buckling on stanene: the role played by spin-orbit coupling and pseudo Jahn-Teller effect

MRS Advances ◽  
2017 ◽  
Vol 2 (29) ◽  
pp. 1563-1569 ◽  
Author(s):  
J. R. Soto ◽  
B. Molina ◽  
J. J. Castro
Keyword(s):  
Dft Calculations ◽  
Group Iv ◽  
Vibronic Coupling ◽  
Coupling Constants ◽  
Orbit Coupling ◽  
Teller Effect ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Jahn Teller ◽  
Jahn Teller Effect

ABSTRACTTwo-dimensional group IV layers beyond graphene, as silicene, germanene and the Sn-based stanene, have been recently synthesized by molecular beam epitaxy. Density Functional Theyory (DFT) calculations predict low-buckled structures for these 2D nanosheets, with a hexagonal honeycomb conformation, typical of the graphene-like surfaces. The buckling parameter δ increases from Si to Sn-based layers, with a maximum predicted of 0.92 Å for stanene. High-buckled structures for these materials resulted to be unstable. We have previously shown that for silicene and germanene, the origin of the buckled structure resides on the pseudo Jahn-Teller puckering distortion, resulting from non-adiabatic effects. It has been shown that hexagermabenzene, the single hexagonal unit of germanene, is subject to a strong vibronic coupling whose origin is the pseudo Jahn-Teller effect. This coupling resulted to be around ten times larger than the one obtained for hexasilabenzene. For stanene, an additional effect needs to be considered to understand the origin of buckling: the spin-orbit coupling (SOC). This SOC contributes to open an electronic band gap, enabling the use of these layers as nanoelectronic components. In this work, we present an analysis based on DFT in the Zeroth-Order Regular Approximation (ZORA) for both scalar relativistic and spin-orbit versions that quantify the influence of the spin-orbit coupling in the puckering of Sn6H6. Also, under the linear vibronic coupling model between the ground and the lowest excited states, we present the pseudo Jahn-Teller contribution. The scalar ZORA approximation is used to perform time-dependent DFT calculations to incorporate the low-energy excitations contributions. Our model leads to the determination of the coupling constants and predicts simultaneously the Adiabatic Potential Energy Surface behavior for the ground and excited states around the maximum symmetry point. These values allow us to compare the Jahn-Teller relevance in buckling with the other group IV layers.

Sign in / Sign up

Export Citation Format

Share Document