Overlap Contributions to the Axial Anisotropy ofMn2+

Results of transferred-hyperfine-interaction (THI) measurements of ${\mathrm{Mn}}^{2+}$ in ${\mathrm{K}}_2$Zn${\mathrm{F}}_4$ were used in conjunction with linear-combination-of-atomic-orbitals theory (involving spin-orbit and intraionic spin-spin interactions) to determine the electronic overlap contributions to the spin-Hamiltonian $D$ parameter of ${\mathrm{Mn}}^{2+}$. For these contributions, the overlap enters the calculation via the normalizing factors of the molecular orbitals. Using overlap integrals determined from the experimental values of the THI tensor, this theory yielded the value of $D=+35.9\mathrm{}\times {10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, which can be compared with the experimental value of +36.0 × ${10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$.