Abstract
An accurate ab initio ground-state intermolecular potential energy surface (PES) was determined for the CO-CO2 van der Waals dimer. The Lanczos algorithm was used to compute rovibrational energies on this PES. For both the C-in and O-in T-shaped isomers, the fundamental transition frequencies agree well with previous experimental results. We confirm that the in-plane states previously observed are geared states. In addition, we have computed and assigned many other vibrational states. The rotational constants we determine from J = 1 energy levels agree well with their experimental counterparts. Planar and out-of-plane cuts of some of the wavefunctions we compute are quite different, indicating strong coupling between the bend and torsional modes. Because the stable isomers are T-shaped, vibration along the out-of-plane coordinates is very floppy. In CO-CO2, when the molecule is out-of-plane, interconversion of the isomers is possible, but the barrier height is higher than the in-plane geared barrier height.
Recommended Citation
E. Castro-Juarez et al., "Computational Study of the Ro-Vibrational Spectrum of CO-CO₂," Journal of Chemical Physics, vol. 151, no. 8, American Institute of Physics (AIP), Aug 2019.
The definitive version is available at https://doi.org/10.1063/1.5119762
Department(s)
Chemistry
Research Center/Lab(s)
Center for High Performance Computing Research
Keywords and Phrases
Carbon dioxide; Dimers; Ground state; Potential energy; Quantum chemistry; Van der Waals forces, Computational studies; Intermolecular potential energy surfaces; Lanczos algorithm; Ro-vibrational energies; Rotational constants; Transition frequencies; Van der Waals dimer; Vibrational state, Isomers
International Standard Serial Number (ISSN)
0021-9606; 1089-7690
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2019 The Authors, All rights reserved.
Publication Date
01 Aug 2019
PubMed ID
31470713
Comments
The authors are thankful for the support from the Canadian Natural Sciences and Engineering Research Council. Richard Dawes and Ernesto Quintas-Sánchez are supported by the U.S. National Science Foundation (Grant No. CHE-1566246).