A Review of the Jahn-Teller Effects (Jahn -Teller, Renner-Teller, and Pseudo Jahn -Teller): The main origin of instability and symmetry breaking of molecular systems

Document Type : Original Article

Author

• Ghazaleh Kouchakzadeh

Department of Chemistry - Faculty of Science- Islamic Azad University- Khorramabad branch- Khorramabad

Abstract

The study of the origin of equilibrium geometry of systems has a long history. Any system wants to stay in a stable state; therefore, the systems are converted from the configuration of high symmetry to the configuration of low symmetry. The origin of systems instability is due to the Jahn-Teller effect. In fact, the Jahn-Teller effect consists of the Jahn -Teller, the Renner-Teller, and the pseudo Jahn –Teller properties. The Jahn- Teller effect is an important mechanism of symmetry breaking in molecular and solid- state systems. The vibronic coupling between the ground state and excited states along the nuclear displacements is assumed as a perturbation, which changes the configuration of systems from a planar geometry with a high symmetry to the bending equilibrium geometry with a lower symmetry. The bending has a significant effect on the prediction of spectroscopic and molecular properties of the systems, as electrical, magnetic, conductivity properties and some other properties can change.

Keywords

• "Symmetry breaking"
• " Jahn- Teller effect"
• "Pseudo Jahn- Teller effect"
• "Renner- Teller effect"
• "Vibronic coupling"
• "Molecular properties"

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