Comparison of Polarization Consistent and Correlation Consistent Basis Sets for Noncovalent Interactions

The convergence of the polarization consistent family of basis sets to the MP2 complete basis set (CBS) limit has been examined for the dissociation energies of five weakly bound clusters: (HF)(2), (HF)(3), (H2O2)(2), (H2O)(3), and (C2H2)(2). MP2 results obtained with two series of polarization consistent basis sets and the analogous series of Dunnings correlation consistent basis sets are compared to the CBS limits obtained with the explicitly correlated MP2-R12 method. Although the polarization consistent basis sets do converge systematically to the CBS limit, the correlation consistent basis sets with diffuse functions on nonhydrogen atoms (i.e., cc-pVXZ for H and aug-CC-PVXZ otherwise) consistently produced the smallest errors. Counterpoise corrections for basis set superposition error did not improve the performance of either the polarization or correlation consistent basis sets. (C) 2008 Wilev Periodicals Inc. Int J Quantum Chem 109: 91-96, 2009