Calculation of fundamental frequencies for small polyatomic molecules: a comparison between correlation consistent and atomic natural orbital basis sets

The performance of the NASA Ames atomic natural orbital (ANO) basis sets for calculating fundamental vibrational frequencies is examined, using the CCSD(T) treatment of electron correlation and second-order vibrational perturbation theory. Particular attention is paid to the performance of the small, cost-effective truncations ([3s 2p 1d] and [4s 3p 2d 1f] on second-row atoms) known as ANO0 and ANO1, as similarly sized basis sets must necessarily be used for high-level correlation treatment of large' molecules. It is found that the ANO0 and ANO1 basis sets - particularly the former - outperform comparably sized correlation consistent basis sets for the calculation of vibrational frequencies, suggesting that the ANO0 basis is a useful tool for this area of computational chemistry.