Systematic testing of Gaussian and complete basis set methods withdispersion corrections for environmentally relevant clusters

Abstract

Results are presented demonstrating the ability of CBS-x and Gn theory to predict energies for non-covalently bound complexes, both uncorrected and upon implementation of dispersion-sensitive DFT.CBS-QCI/APNO performs best among uncorrected methods (MUE 0.88 kcal mol−1), while G4 (MUE1.05 kcal mol−1) and CBS-QB3 (MUE 1.13 kcal mol−1) provide energies close to that of CBS-QCI/APNO,but at a reduced cost. Inclusion of B2PLYP-D and B97-D as well as M0N-2X type functionals intoG4 and CBS-QB3 results in improved binding energies. From a comparison with CCSD(T)/CBS results,M05-2X/CBS-QB3 structures and binding energies provide a cost-effective and accurate description ofenvironmentally relevant non-covalent interactions.