Hyperfine Structure in Trivalent Plutonium

Abstract

The hyperfine structure constants of ${\mathrm{Pu}}^{3+}$ in Ca${\mathrm{F}}_2$, Sr${\mathrm{F}}_2$, and Ba${\mathrm{F}}_2$ are analyzed and the values $〈\frac{1}{r^3}〉=7.\mathrm{}57\pm 0.57$ a.u. and ${a_{c_{\mathrm{Pu}}}}^{3+}=-(556\mathrm{}\pm 42) (g_J-1)\left(\frac{{\mu }_N}{I}\right)$ Mc/sec are derived. Relativistic Dirac-Slater and Dirac-Fock wave functions give a value for $〈\frac{1}{r^3}〉$ about 9% lower than the empirical value. The core-polarization effect in the actinide ion ${\mathrm{Pu}}^{3+}$ is much larger than in the lanthanide series.