Many-body Convergence of the Interaction Energies in CO₂ Systems

Jasmine Cherry and Olaseni Sode

The University of Tampa, Department of Chemistry, Biochemistry, and Physics

The importance of CO₂ injection in enhanced oil recovery, sequestration using metal organic frameworks, and crystal structure prediction make the systematic study of carbon dioxide essential. Importantly, a clear description of the many-body properties of CO₂ is especially necessary when considering condensed phase applications. In order to address this issue, a hierarchy of wavefunction theory methods was used to clarify the energetic properties of carbon dioxide. We explore the many-body convergence of the electronic energy for clusters of carbon dioxide containing as many as five molecules up to the CCSD(T)-F12 level of theory with an aug-cc-pVDZ basis set. Also, we remark on the fast decay of the three-body and higher terms at increasing intermolecular distances in isomers of the carbon dioxide trimer, tetramer, and pentamer.