A New Basis Set for the Calculation of 13C NMR Chemical Shifts within a Non-empirical Correlated Framework.

A new basis set of triple-ζ quality for carbon, 3z-S, is developed and tested at the DFT, MP2, and CCSD(T) levels, taking into account solvent and vibrational corrections for a number of molecules ranging from the smallest fluoromethane, CH3F, to the largest 5,10,15,20-tetraphenylporphyrin, C44H30N4. The proposed highly economical 3z-S basis set has been proven to provide very good accuracy in all examinations, comparable to that of the NMR-oriented Jensen's pcS-2 basis set, which is about 50% larger than 3z-S.