Electron affinities and hyperfine structure for U- and U i obtained from relativistic configuration-interaction calculations

Valence-shell relativistic configuration-interaction calculations predict one U- bound state, viz., 5f36d7s27p J=13/2, with an electron affinity of 0.175 eV. We found no other Js for this configuration to be bound, nor are any 5f36d27s2 levels expected to be bound. Attachment of a 5f electron is even more unlikely. The hyperfine structure (hfs) constants for the U-235 state, in MHz, are, respectively, A,B=-72.4,2644. Although core polarization effects are absent, the valence hfs results for i235 are in generally good agreement with experiment and represent a modest improvement compared to existing semiempirical values. An LS analysis is provided for the bound state. © 1995 The American Physical Society