Spin-orbit corrections to the indirect nuclear spin-spin coupling constants in XH4 (X = C, Si, Ge, and Sn)

Abstract

Using the quadratic response function at theab initio SCF level of approximation we have calculated the relativistic corrections from the spin-orbit Hamiltonian,H SO, to the indirect nuclear spin-spin coupling constants of XH4 (X = C, Si, Ge, and Sn). We find that the spin-orbit contributions toJ X-H are small, amounting only to about 1% forJ Sn-H. For the geminal H-H coupling constants the relativistic corrections are numerically smaller than forJ X-H, but in some cases relatively larger compared to the actual magnitude ofJ H-H. We also investigate the use of an effective one-electron spin-orbit Hamiltonian rather than the fullH SO in the calculation of these corrections.