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Relativistic coupled-cluster calculations on XeF6: Delicate interplay between electron-correlation and basis-set
Lan Cheng1, Jürgen Gauss2, John F Stanton1
1Department of Chemistry, Institute for Theoretical Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
The Journal of Chemical Physics
|June 15, 2015
Summary
This study investigates the vibrational frequencies of Xenon Hexafluoride (XeF6) conformers using relativistic coupled-cluster methods. Results indicate that the O(h) and C(3v) structures are stable, while C(2v) is a transition state.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Molecular Spectroscopy
Background:
- Xenon Hexafluoride (XeF6) exhibits complex conformational behavior.
- Understanding its potential energy surface is crucial for predicting its properties.
Purpose of the Study:
- To systematically investigate the harmonic vibrational frequencies of XeF6 conformers.
- To accurately determine the stability of different XeF6 structures using relativistic quantum chemical methods.
Main Methods:
- Relativistic coupled-cluster calculations.
- Spin-free exact two-component (SFX2C-1e) theory for scalar-relativistic effects.
- Atomic natural orbital basis sets recontracted for SFX2C-1e.
Main Results:
- The O(h) and C(3v) conformers of XeF6 are predicted to be local minima.
- The C(2v) conformer is identified as a transition state.
- Basis set convergence for vibrational frequencies was rapidly achieved.
Conclusions:
- The SFX2C-1e method provides reliable vibrational frequencies for XeF6.
- Discrepancies with previous calculations are attributed to basis set sensitivity in specific vibrational modes.
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