Here, r is the unit vector pointing from the paramagnetic center (in the NiSAL-HDPT complex: the location of the Ni nucleus) to the magnetic nucleus, r is the distance between paramagnetic center and nucleus, (r ⊗ r) aniso denotes the anisotropic/traceless part of the dyadic tensor constructed from r, i.e., (r ⊗ r) aniso ij = ri rj -1 3 δ ij , and the electronic magnetic moment operator is given by