The societal impacts of the carbon dioxide molecule—from its industrial applications to its environmental consequences—make its behavior of particular interest to the scientific community. In order to explain this behavior in the gas, liquid, solid and supercritical phases, understanding the interactions between CO2 molecules is crucial. Notably, molecular vibrations are sensitive to these intermolecular interactions, and they have been used to determine the structure of small molecular clusters. We address the vibrational structure of the CO2 monomer, dimer and two trimer isomers (the cyclic and barrel-shaped structures) and compare our results to experimental values when possible. Traditional wavefunction theory (WFT) methods, including Hartree-Fock, second-order Møller-Plesset perturbation theory, and coupled cluster are used with increasingly large basis sets (up to the aug-cc-pVQZ) within the harmonic approximation to determine the vibrational energy levels for the CO2 systems. Also, we compute the infrared and Raman spectra using the M06-2X density functional. Lastly, we employ a newly developed CO2 potential [O. Sode, J. N. Cherry, J. Comput. Chem., (2017)] fit to the CCSD(T)-F12/aug-cc-pVTZ level of theory to perform dynamics simulations on the CO2 systems.

Exploration of the molecular vibrations of small carbon dioxide clusters with ab initio electronic structure methods

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.