Spin–orbit corrections to the indirect nuclear spin–spin coupling constants in XH

Correlated response calculations of the spin-orbit interaction contribution to nuclear spin-spin couplings

“…In contrast, no such limitation is present for any of the shielding corrections 10,11,19 or the third-order coupling corrections. 12 For couplings between light ligand nuclei in the presence of heavy elements, the second-order coupling corrections are also expected to be well-behaved.…”

“…The third-order contributions arising from the field-free SO Hamiltonian are, neglecting terms involving three simultaneous triplet perturbations as rationalized by Kirpekar et al 12 :…”

“…12 were limited to the uncorrelated SCF level, and because even the nonrelativistic spin᎐spin coupling tensors are known to be highly dependent on the electron correlation treatment, it appears necessary to investigate the SO corrections at the correlated level. It is also of interest to study compounds that can be expected to be more affected by the SO interaction than the group 14 hydrides studied by Kirpekar et al 12 Finally, a comparison of correlated first principles calculations of the SO corrections with experimental data will indirectly give information about the importance of scalar relativistic interactions on spin᎐spin couplings.…”

“…In this study, we use the previously proposed third-order formulation of Kirpekar et al, 12 and introduce the novel second-order terms arising from the magnetic field dependence of the SO Hamiltonian, to calculate the relativistic SO interaction contributions to spin᎐spin coupling tensors. …”

Indirect NMR spin–spin coupling constants in diatomic alkali halides

“…13,14 The relativistic effects can be interpreted by applying perturbation theory; 15 for example, the effects caused by the interplay between the Fermi-contact (FC) interaction of nucleus K with the spinorbit (SO) interaction generated by the magnetic moment of nucleus L can be analyzed. [16][17][18] On the other hand, to include most of the relevant one-and two-electron relativistic corrections into the calculation of indirect spin-spin coupling constants in a more systematic way, it is convenient to start from two-component [19][20][21] or four-component [22][23][24][25] relativistic Hamiltonians. In this way, both scalar and spin-orbit relativistic corrections are included into the wave function variationally and thus relativistic effects to arbitrary order are accounted for.…”