Gaussian basis sets for correlated wave functions. Hydrogen, helium, first- and second-row atoms

Contracted basis sets of double zeta (DZ) valence quality for H, He, first- and second-row atoms are constructed from fully-optimized Gaussian basis sets generated in this work. A single set of Gaussian polarization functions (d symmetry) optimized at the M phi ller-Plesset second-order (MP2) level was added to the DZ set. Then, this set is augmented with diffuse (s and p symmetries) and polarization (d symmetry) functions that were optimized for the anion at the HF and MP2 levels, respectively. The accuracy of the sets generated in this work is compared with the widely used correlation consistent basis sets of Dunning et al. (c) 2005 Elsevier B.V. All rights reserved.