A variational method for calculating nuclear spin-spin interactions in molecules

A general variation method is developed for determining: (a) the magnetic shielding of nuclear spin-spin interactions in molecules; (b) the electron-coupled nuclear spin-spin interactions in molecules. Using simple valence-bond and molecular-orbital wave functions calculations have been made for the HD molecule. It is concluded that effect (a) is small compared with (b). Both wave functions lead to values for the zero magnetic field splitting of about 49 c/s, in good agreement with the observed value of 43 c/s.