An evaluation of the performance of diffuse function‐augmented basis sets for second row elements, Na‐Cl

Abstract
The energetic effects of the addition of diffuse functions to molecules with second‐row elements are much less dramatic than those for their first‐row counterparts. Although diffuse functions on second‐row elements have little effect on the geometries and vibrational frequencies of neutral molecules, significant changes are found for anions. While the largest basis set, 6‐31 + G*, generally performs best, the results at 3‐21 + G* are comparable, and this basis can be recommended for practical applications.