The electron correlation contribution to the nuclear magnetic shielding tensor of the hydrogen molecule

The nuclear magnetic shielding tensor and the spin-rotation constant of the hydrogen molecule have been studied at the full configuration interaction level using a sequence of systematically enlarged basis sets which allow extrapolation to the basis set limit. The computed and experimental values for the isotropic shielding constant and the spin-rotation constant agree within 0.03 ppm and 0.3 kHz, respectively. The present values for the shielding tensor and the spin-rotation constant differ by 0.15–0.20 ppm and 2.5 to 2.9 kHz, respectively, from the values recently obtained in calculations using exponentially correlated Gaussian functions.