Core-valence Gaussian basis sets of double and triple zeta quality for Li to Ar. Applications in calculations of indirect nuclear spin-spin coupling constants

► We added tight functions at the XZP basis sets (X = D, T). ► Description of electron correlation energy in core region was improved. ► Applying the Woon and Dunning's method we generated new CXZP (X = D, T) basis sets. ► We did calculations of NMR indirect spin-spin coupling constants for nine molecules. ► We showed that the CXZP sets provided best values of coupling constants.