Coupled Cluster Theory Combined with Reference Interaction Site Model Self-Consistent Field Explicitly Including Spatial Electron Density Distribution

J Chem Theory Comput. 2018 May 8;14(5):2661-2666. doi: 10.1021/acs.jctc.8b00168. Epub 2018 Apr 4.

Abstract

Calculating the geometry and energy of a molecule in a solution is one of the most important tasks in chemistry. However, performing an accurate calculation in a solution is still a difficult task because the electronic structure and solute-solvent interactions are required to be accurately evaluated with an efficient computational cost. To overcome this difficulty, we proposed the coupled cluster with single and double excitations and perturbative triple excitations combined with the reference interaction site model (RISM) by employing our fitting approach. Our method correctly reproduced the relative stabilities of 1,2,3-triazole, isonicotinic acid, cytosine, and 6-chloro-2-pyridone in the aqueous phase, whereas the dielectric continuum model provided incorrect results for isonicotinic acid and 6-chloro-2-pyridone. Our method provided accurate results because the RISM captured the local solvation structure, such as hydrogen bonds.