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Computational study of rovibrational spectra of Van der Waals dimers and their isotopologues

A new intermolecular potential energy surface, rovibrational transition frequencies, and line strengths are computed for OCS-OCS and CO2-CS2. The potentials were made by fitting energies obtained from explicitly correlated coupled-cluster calculations and fit using an interpolating moving least squares method. Rovibrational transition frequencies are also calculated for four isotopologues of the N2O dimer using a previously presented potential energy surface. The rovibrational Schroedinger equation for all three dimers is solved with a symmetry-adapted Lanczos algorithm and an uncoupled product basis set. All four intermolecular coordinates are included
in the calculation.

On the OCS-OCS potential energy surface, a previously unknown, cross-shaped
isomer is found along with polar and non-polar isomers. For CO2-CS2, the previously found cross-shaped minima is found along with a slipped-parallel configuration. The associated wavefunctions and energy levels for each of these isomers is presented. To identify states that have a permanent dipole, both calculations of line strengths and vibrational parent analysis is used. For non polar states of, OCS-OCS, and N2O-N2O isotopologues, and all CO2-CO2 states, only vibrational parent analysis was used. Calculated rotational constants differ from their experimental counterparts by less
than 0.001 wavenumbers for OCS-OCS and CO2-CS2, and less than 0.002 wavenumbers for any N2O-N2O isotopologue. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2012-08-23 13:19:45.294

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/7405
Date29 August 2012
CreatorsBrown, JAMES
ContributorsQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish, English
Detected LanguageEnglish
TypeThesis
RightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
RelationCanadian theses

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