Spin-rotation interaction and magnetic shielding inΣ1molecules

Abstract
The theory of the spin-rotation interaction is discussed and its relation to the paramagnetic part of the magnetic shielding tensor derived with consistent treatment of the electric field in the molecule. The latter point yields agreement between theory and experiment for the first time in the case of isotopes of the hydrogen molecule. The paramagnetic part of the shielding constant for H2 (J=1) is found to be -5.66(6) × 106 in the gauge where the vector potential is zero at the nucleus.