Ab Initio Calculation Applied To The Study Of Organic Non-rigid Molecules With (at Least) Three Torsional Modes

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https://hdl.handle.net/2142/111170

Title: Ab Initio Calculation Applied To The Study Of Organic Non-rigid Molecules With (at Least) Three Torsional Modes
Author(s): Senent, Maria Luisa S
Issue Date: 2021-06-23
Keyword(s): Mini-symposium: Large Amplitude Motions
Abstract: Methods applicable to the spectroscopic study of non-rigid organic molecular species with various large amplitude motions (torsions and inversions), are shown. Recent studies of ethylene glycol, \chem{C_3O_6H_6} isomers, and other species containing C, H, O, and N are employed as examples. Many organic molecules display non-rigidity. Vibrational modes (inversions and torsions) interconvert different conformers separated by relatively low barriers. Some conformers can be stabilized by the presence of hydrogen intermolecular bonds that can determine their geometry, symmetry, the shape of the potential energy surface and the internal dynamics. When a species displays three or more large amplitude motions, which cannot be separated because they interact strongly, the variational calculation of vibrational levels is complex and requires to search for ways reducing computational efforts. Especially tricky is the classification of the vibrational levels and their splittings.
Publisher: International Symposium on Molecular Spectroscopy
Type of Resource: Text
Language: eng
Permalink: http://hdl.handle.net/2142/111170
DOI: 10.15278/isms.2021.WA01