Truncation of the correlation consistent basis sets: An effective approach to the reduction of computational cost?

The systematic reduction of commonly used basis sets as a means to reduce computational cost is examined for a small test set of molecules, which includes H-2, CH4, NH3, H2O, HF, and HCN. Coupled cluster with single, double, and quasiperturbative triple excitations calculations were performed using both the correlation consistent basis sets, and a set of systematically reduced basis sets to examine both the impact of the reduction upon the accuracy of the structures and energies, and the computational cost savings achieved. The effect of several truncation scenarios upon basis set convergence is also examined. Overall, for the systems studied, a reduction can occur which preserves the well-established systematic convergence behavior of the correlation consistent basis sets. (C) 2004 American Institute of Physics.