Figure 2

Distinguishing the long-range “mediated” interaction from the direct exchange interaction. (a) The direct exchange interaction J_DR as a function of the H–H distance (d_H-H). (b) Extracting the long-range “mediated” interaction \({J}_{LR}^{{\rm{FM}}}\) from the linear relation between ∆M^* and ∆E^* in Eq. 2. The selected H pairs, labeled 1, 2, and 3, are shown in the inset of (a). For a given pair type, the DFT data lie almost on a straight line with a slope of \(-{J}_{LR}^{{\rm{FM}}}\), and the absolute value of the y-intercept corresponds to \({J}_{DR}^{{\rm{pair}}}\). The fitted \({J}_{DR}^{{\rm{pair}}}\) values for the selected H pairs are shown as open squares in (a).