Linker IT Software
menubar-top-links menubar-top-rechts
Home Help Search Login
Welcome, Guest. Please Login.
SQL*XL: Database to Excel bridge litLIB: Excel power functions pack ExcelLock: Locking and securing your valuable Excel spreadsheets encOffice: Protect your Excel file easy and safe encOffice: Protect your Excel file easy and safe
Pages: 1
Jahn-Teller effect (Read 2710 times)
Gerrit-Jan Linker
YaBB Administrator

Posts: 75
Jahn-Teller effect
02.04.09 at 10:34:23
Jahn-Teller effect
Synonyms: The Jahn–Teller effect, The Jahn-Teller distortion, the Jahn-Teller theorem.
The Jahn-Teller (JT) effect deals with molecular distortions due to an electronically degenerate ground state.  
The HT effect describes the geometrical distortion of non-linear molecules under certain situations. It can be proven using group theory, that non-linear degenerate molecules cannot be stable.  
Any non-linear molecule with a degenerate electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the complex.
For nonlinear molecular entities in a geometry described by a symmetry point group possessing degenerate irreducible representations there always exists at least one nontotally symmetric vibration that makes the electronic states with orbital degeneracy unstable at this geometry.  
First-order Jahn-Teller effect
The nuclei are displaced to new equilibrium positions of lower symmetry causing a splitting of the originally degenerate electronic
Renner−Teller effect
For linear molecules.
Pseudo Jahn-Teller or second-order Jahn-Teller effect
In the case of molecules with a nondegenerate ground electron state, but with a very low lying excited state, distortions of proper symmetry arise which mix ground and excited states, and thereby lower the ground state energy.  
The closer the states in energy, the more effective is the mixing.  
Jahn–Teller effect - Wikipedia
Back to top
« Last Edit: 07.10.14 at 11:19:16 by Gerrit-Jan Linker »  

Gerrit-Jan Linker
Linker IT Software
Email WWW Gerrit-Jan Linker   IP Logged
Pages: 1