Selected-Nuclei Method for the Computation of Hyperfine Coupling Constants within Second-Order Møller-Plesset Perturbation Theory.

We introduce a new ansatz to compute hyperfine coupling constants of selected nuclei at the level of second-order Møller-Plesset perturbation (MP2) and double-hybrid density functional theory with reduced computational effort, opening the route to the analyis of hyperfine coupling constants of large molecular structures. Our approach is based on a reformulation of the canonical MP2 term in atomic orbitals, thus exploiting the locality of electron correlation. We show that a perturbation-including integral screening reduces the scaling behavior of the number of significant two-electron integrals to sublinear. This selected-nuclei approach allows for an efficient computation within scaled-opposite spin (SOS) RI-MP2 on massively parallelized architectures such as graphical processor units (GPUs), thus enabling studies on the influence of the environment on hyperfine coupling constants.