GIAO shielding constants and indirect spin–spin coupling constants: performance of density functional methods

The performance of the KT1 and KT2 exchange-correlation functionals is assessed for the determination of GIAO nuclear magnetic resonance shielding constants and indirect spin–spin coupling constants. For 14 highly correlated molecules containing light, main group nuclei, the functionals provide isotropic shieldings that are more than twice as accurate as those of BLYP and B3LYP. For 11 other molecules, they provide spin–spin coupling constants that are of variable quality. The spin–spin results highlight the sensitivity of the Fermi-contact term to exchange-correlation functional and are consistent with previous observations using a self-interaction corrected functional.