Calculation of Atomic Hyperfine Structure Constants from Projected Unrestricted Hartree-Fock Functions. Constants ofF19

Abstract

The magnetic hyperfine constants for the ${}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ and ${}_{}{}^2{}_{}{}^{}P_{\frac{1}{2}}^{}{}_{}{}^{}$ states of $F^{19}$ are calculated from the projected unrestricted Hartree-Fock (UHF) function where the orbitals are linear combinations of analytic functions. Neglecting the nonorthogonality between the radial parts of spin $\alpha$ and spin $\beta$ functions, the values obtained are (experimental results are given in parentheses): $a^{\prime }=2031\mathrm{}$ Mc/sec (2010 Mc/sec), $a^{\prime \prime \prime }=522\mathrm{}$ Mc/sec (446 Mc/sec), $a^{\prime \prime }=9952\mathrm{}$ Mc/sec (10 244 Mc/sec). The contribution coming from the Fermi contact operator calculated from the projected UHF function is in much better agreement with experiment than that calculated either from the UHF or configuration interaction functions.