Automatic generation of complementary auxiliary basis sets (CABS) for explicitly correlated methods

Abstract

Explicitly correlated calculations, aside from the orbital basis set, typically require three auxiliary basis sets: JK (Coulomb-exchange fitting), RI-MP2 (resolution of the identity MP2), and CABS (complementary auxiliary basis set). If unavailable for the orbital basis set and chemical elements of interest, the first two can be auto-generated on the fly using existing algorithms, but not the third. In this paper, we present a quite simple algorithm named autoCABS; a Python implementation under a free software license is offered at Github. For the cc-pVnZ-F12 (n=D,T,Q,5) and the W4-08 thermochemical benchmark, we demonstrate that autoCABS-generated CABS basis sets are comparable in quality to purpose-optimized OptRI basis sets from the literature, and that the quality difference becomes entirely negligible as n increases.

18 pages; new section on harmonic frequencies added

References in corpus (5)

• The cc-pV5Z-F12 basis set: reaching the basis set limit in explicitly correlated calculations
• The aug-cc-pVnZ-F12 Basis Set Family: Correlation Consistent Basis Sets for Explicitly Correlated Benchmark Calculations on Anions and Noncovalent Complexes
• The S66 noncovalent interactions benchmark reconsidered using explicitly correlated methods near the basis set limit
• Straightforward and accurate automatic auxiliary basis set generation for molecular calculations with atomic orbital basis sets
• Automatic generation of complementary auxiliary basis sets (CABS) for explicitly correlated methods

Cited by in corpus (2)

• Towards Pair Atomic Density Fitting for Correlation Energies with Benchmark Accuracy
• Automatic generation of complementary auxiliary basis sets (CABS) for explicitly correlated methods