Postprint version. Published in Chemical Physics Letters, Volume 14, Issue 5, July 1, 1972, pages 561-562.
NOTE: At the time of publication, the author Richard B. Frankel was not yet affiliated with Cal Poly.
The definitive version is available at https://doi.org/10.1016/0009-2614(72)87207-5.
Analysis of magnetic hyperfine interactions of Fe2+ in FeF2, Fe2+:MnF2 and Fe2+:ZnF2 yields a core polarization hyperfine field Hc = −514 ± 30 kOe and a value of (r−3)eff = 3.9 ± 0.04 au.