Benchmark correlation consistent basis sets

In the present work, correlation consistent basis sets have been developed for the transition metal atoms Y and Hg using small-core quasirelativistic PPs, i.e., the ns and (nA)d valence electrons as well as the outer-core (nA)sp electrons are explicitly included in the calculations. This can greatly reduce the errors due to the PP approximation, and in particular the pseudo-orbitals in the valence region retain some nodal structure. Series of basis sets from double-through quintuple-zeta have been developed and are denoted as cc-pVwZ-PP (correlation consistent polarized valence with pseudopotentials). The methodology used in this work is described in Sec. II, while molecular benchmark calculations on YC, HgH, and Hg2 are given in Sec. III. Lastly, the results are summarized in Sec. IV. 

In order to benchmark the ECP results for Hg, all-electron correlation consistent basis sets were also developed both with and without the inclusion of... 

Jurecka et al have published a database of accurate benchmark quality interaction energies of small model complexes, DNA base pairs, and amino acid pairs obtained from MP2 and CCSD(T) calculations together with estimates of the complete basis set limit. They examine interaction energies and geometries for more than 100 DNA base pairs, amino acid pairs and model complexes. Extrapolation to the complete basis set limit was carried out by these researchers using a two-point method in conjunction with correlation consistent basis sets. 

As auxiliary RI correlation consistent basis sets have been optimized, an RI-ccCA implementation was created by Prascher and Wilson [154], replacing all MP2 steps with their equivalent RI-MP2 computations, and the CCSD(T)-additive correction with the local RI-CCSD(T) method developed by Schiitz and Werner [159-161]. Correlation consistent auxiliary basis sets developed by Weigend [162] were utilized for the various ccCA steps. Benchmark computations on 102 closed... 

In our benchmark studies of correlated molecular calculations, we will focus largely on diatomic and triatomic molecules because, for these systems, it is possible to carry out calculations with the full range of correlation consistent basis sets. This allows us to establish definitively the complete basis set limits of the properties of interest, i.e., Only... 

The basis set requirements needed to accurately compute the core-core correlation is rather severe. Molecular calculations indicate that the basis set requirements to obtain the core-valence contribution are somewhat less stringent, but the basis set requirements are not well defined. The core-valence correlation consistent basis sets of Woon and Dunning should help benchmark the basis set requirements as they provide sets which are systematically expandable. 

Peterson KA, Yousaf KE. Molecular core-valence correlation effects involving the post-d elements Ga-Rn Benchmarks and new pseudopotential-based correlation consistent basis sets. J Chem Phys. 2010 133 174116. 

Basis Sets Correlation Consistent Sets Benchmark Studies on Small Molecules Coupled-cluster Theory Gradient Theory M0ller-Plesset Perturbation Theory NMR Chemical Shift Computation Ab Initio Spin Contamination Symmetry in Chemistry. 

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