Systematically convergent basis sets with relativistic pseudopotentials. I. Correlation consistent basis sets for the post-d group 13–15 elements

New correlation consistent-like basis sets have been developed for the post-d group 13–15 elements ~Ga–As, In–Sb, Tl–Bi! employing accurate, small-core relativistic pseudopotentials. The resulting basis sets, which are denoted cc-pVnZ-PP, are appropriate for valence electron correlation and range in size from (8s7p7d)/@4s3p2d# for the cc-pVDZ-PP to (16s13p12d3 f 2g1h)/ @7s7p5d3 f 2g1h# for the cc-pV5Z-PP sets. Benchmark calculations on selected diatomic molecules (As2 , Sb2 , Bi2 , AsN, SbN, BiN, GeO, SnO, PbO, GaCl, InCl, TlCl, GaH, InH, and TlH! are reported using these new basis sets at the coupled cluster level of theory. Much like their all-electron counterparts, the cc-pVnZ-PP basis sets yield systematic convergence of total energies and spectroscopic constants. In several cases all-electron benchmark calculations were also carried out for comparison. The results from the pseudopotential and all-electron calculations were nearly identical when scalar relativity was accurately included in the all-electron work. Diffuse-augmented basis sets, aug-cc-pVnZ-PP, have also been developed and have been used in calculations of the atomic electron affinities. © 2003 American Institute of Physics. @DOI: 10.1063/1.1622923#