Basis sets convergence of correlated calculations

Helgaker, T., Klopper, W., Koch, H., Noga, J. Basis-set convergence of correlated calculations on water. J. Chem. Phys. 1997, 106, 9639-46. 

Table 1. The basis-set convergence of the Cauchy moments S(k) [a.u.] for Ne calculated with CCSD model and the n-aug-cc-VXZ basis-set family (all electrons correlated)...

Table 3. Basis set convergence of first hyperpolarizabilities (Sj (in a.u.) at the (unrelaxed) CCSD level. For FH. CO, and HjO results are given for the static limit /3 (0), while for HCl the results are for 6 (—ft), ft), 0) with i = 0.072003 a.u. (632.8 nm). In all calculations a frozen core approximation with the electrons in the ks shells of non-hydrogen atoms kept inactive in the correlation and response calculations is employed...

Nevertheless, as for atomization eneigies, we expect the basis-set convergence of the enthalpies to he dominated hy the errors in the correlation treatment. For this reason, we shall here attempt to carry out extrapolations of the correlation part of the enthalpy, applying the procedure described in Section 15.6.1. In Table 15.32, we have listed the usual statistical measures of errors for the ealculated and extrapolated all-electron CCSD(T) reaction enthalpies. In Figure 15.17, we have plotted the normal distributions of the errors in the calculated reaction enthalpies, with and without extrapolation. 

---