Truncation of the correlation consistent basis sets: Application to extended systems

The systematic reduction of the correlation consistent basis sets [cc‐pV n Z, where n = D (2), T (3), and Q (4)] for the hydrogen atom as a means to reduce the computational cost of ab initio calculations has been extended to methane through decane and the hydrogen‐containing molecules of the G3/99 test suite. Møller–Plesset second‐order perturbation theory single‐point computations were performed with the full and truncated cc‐pV n Z basis sets utilizing the B3LYP/6‐31G(d) density functional optimized geometry. Complete basis set (CBS) limits were determined for atomization energies utilizing the full cc‐pV n Z basis set series and several truncated basis set series. The difference between the CBS limit for atomization energies determined with a series of truncated basis sets as compared to that of the full basis set series is relatively constant from molecule to molecule. We introduce a correction factor per hydrogen, which when paired with CBS limits determined with a series of truncated basis sets results in errors in atomization energies of less than 0.5 kcal/mol from CBS limits determined with a series of full basis sets. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007