Ab initiostudy ofSrFexTi1−xO3: Jahn-Teller distortion and electronic structure

2008 ◽  
Vol 77 (7) ◽  
Author(s):  
V. E. Alexandrov ◽  
J. Maier ◽  
R. A. Evarestov
Keyword(s):  
Electronic Structure ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion

Intrinsic Defects in GaAs - the Case of El2

1987 ◽  
Vol 104 ◽  
Author(s):  
H. J. Von Bardeleben ◽  
D. Stievemard
Keyword(s):  
Electronic Structure ◽  
Stable Configuration ◽  
Theoretical Studies ◽  
Absorption Bands ◽  
Teller Distortion ◽  
Jahn Teller ◽  
The Stability ◽  
Additional Support ◽  
Jahn Teller Distortion ◽  
Experimental And Theoretical Studies

ABSTRACTThe arsenic antisite-arsenic interstitial pair model for the stable configuration of the EL2 defect in GaAs has stimulated new experimental and theoretical studies, the results of which lead to additional support for this model. Recent theoretical studies, taking into account the effect of a Jahn Teller distortion of the T2 Asi levels have given an insight into the stability and the electronic structure of the defect pair. Further, ODENDOR studies have directly confirmed this model and allowed one to specify the lattice location and the charge state of the Asi ion. The pair structure of this defect implies a reconsideration of the charge states of the EL2 defect, as well as the origin of the optical absorption bands for which transitions on the Asi ion and intracenter bands have also to be considered. The model leads further to a description of the metastable configuration : an arsenic molecule at the gallium vacancy site, the electronic structure of which is calculated. The vacancy related defects, known from electron irradiation studies, are not detected in LEC grown GaAs as native defects.

Vacancy induced Jahn–Teller distortion in silicon and its influence to the electronic structure

2015 ◽  
Vol 29 (24) ◽  
pp. 1550136
Author(s):  
Shuying Zhong ◽  
Xueling Lei ◽  
Lang Zhou
Keyword(s):  
Electronic Structure ◽  
Charge Density ◽  
First Principles ◽  
Electronic Structures ◽  
Crystalline Silicon ◽  
First Principles Calculations ◽  
Teller Distortion ◽  
Jahn Teller ◽  
The Difference ◽  
Jahn Teller Distortion

Atomic and electronic structures of monovacancy (V1), divacancy (V2) and ring hexavacancy (V6) in crystalline silicon are studied using first-principles calculations in periodic supercells. Our results show that the V6 defect is the most stable among V1, V2 and V6 defects, and the V2-RB structure is a little more stable than the V2-LP structure due to lower vacancy formation energy. Furthermore, it is found that both V1 and V2 undergo the Jahn–Teller (JT) distortion while V6 does not. As a result, V1 and V2 have deep levels in the gap which mainly come from the neighboring atoms to vacancy. V6 has tailing bands in the gap, and so has a more stable electronic structure than V1 and V2. In addition, the JT distortion also reflects in the band decomposed charge density and the difference charge density.

GEOMETRICAL AND ELECTRONIC STRUCTURE OF C60 ANIONS

1992 ◽  
Vol 06 (23n24) ◽  
pp. 3853-3858 ◽  
Author(s):  
Sven Stafström
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Bond Length ◽  
Density Of States ◽  
Bond Order ◽  
Coulomb Interactions ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion ◽  
Spherical Molecule

The geometrical and electronic structure of various C 60 anions is calculated using a model which couples the bond length to the bond order and to Coulomb interactions between adjacent sites. The total energy of the C 60 anions is minimized with respect to variations in the bond length. The geometrical relaxations of the anions, relative to the neutral molecule, are such that the symmetry of the molecule is lowered (Jahn-Teller distortion). In the case of the mono-anion and the di-anion, the geometrical distortions and the charge are localized to one equatorial line around the spherical molecule. We term this type of self-localized defect a cyclon. The distortions of higher anions are best described as resulting from interacting cyclons. These distortions and the corresponding charges are delocalized over practically the whole system. The Jahn-Teller distortions of the C 60 anions result in a breaking of the degeneracy of the electronic levels and, generally speaking, a broadening of the peaks in the density of states compared to neutral C 60.

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