Restricted magnetically balanced basis applied for relativistic calculations of indirect nuclear spin–spin coupling tensors in the matrix Dirac–Kohn–Sham framework
Michal Repiskýa, Stanislav Komorovskýa, Olga L. Malkinaa and Vladimir G. Malkin
The relativistic four-component density functional approach based on the use of restricted magnetically balanced basis (mDKS-RMB), applied recently for calculations of NMR shielding, was extended for calculations of NMR indirect nuclear spin–spin coupling constants. The unperturbed equations are solved with the use of a restricted kinetically balanced basis set for the small component while to solve the second-order coupled perturbed DKS equations a restricted magnetically balanced basis set for the small component was applied. Benchmark relativistic calculations have been carried out for the X–H and H–H spin–spin coupling constants in the XH4 series (X = C, Si, Ge, Sn and Pb). The method provides an attractive alternative to existing approximate two-component methods with transformed Hamiltonians for relativistic calculations of spin–spin coupling constants of heavy-atom systems. In particular, no picture-change effects arise in our method for property calculations.