The Jahn-Teller effect as a treatment of molecular anharmonicity

Perry, David S.

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https://hdl.handle.net/2142/100831 Copy

Description

Title

The Jahn-Teller effect as a treatment of molecular anharmonicity

Author(s)

Perry, David S.

Contributor(s)

• Dawadi, Mahesh B.
• Thapaliya, Bishnu P.

Issue Date

2018-06-19

Keyword(s)

Mini-symposium: New Ways of Understanding Molecular Spectra

Abstract

An important aspect of vibrational anharmonicity results from the substantial changes in molecular geometry and bonding that occur in the coordinate space of large-amplitude nuclear motion. Examples of such largeamplitude motion include torsional motion, inversion, the intermolecular motions within clusters, and reaction coordinates. Here we show that the Jahn-Teller formalism, when suitably extended, provides a precise description of the variation of the small-amplitude vibrational frequencies in a large-amplitude coordinate space. The locations where the smallamplitude frequencies cross are vibrational conical intersections (CIs) and multiple CIs may occur in one molecular system. In this work, we expand the motion of one molecular fragment relative to the other in spherical harmonics to allow an even-handed treatment of large-amplitude motion in 4π steradians. The molecular systems treated include CH3OH, CH3SH, and the complexes of CH4 with F− and Na+ ions. The Jahn-Teller formalism provides a general treatment of near-resonant interactions including their explicit dependence on large-amplitude nuclear coordinates. It also includes a crude adiabatic basis, which allows for convenient computation of the fully coupled quantum nuclear dynamics. The opportunities and limitations of this approach will be discussed.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100831

DOI

10.15278/isms.2018.TB05

Copyright and License Information

Copyright 2018 David S. Perry

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