ELECTRON-AFFINITIES AND HYPERFINE-STRUCTURE FOR U- AND U-I OBTAINED FROM RELATIVISTIC CONFIGURATION-INTERACTION CALCULATIONS

Valence-shell relativistic configuration-interaction calculations pred ict one U- bound state, viz., 5f(3)6d7s(2)7p J = 13/2, with an electro n. affinity of 0.175 eV. We found no other J's for this configuration to be bound, nor are any 5S(3)6d(2)7s(2) levels expected to be bound. Attachment of a 5f electron is even more unlikely. The hyperfine struc ture (hfs) constants for the U-235(-) state, in MHz, are, respectively , A,B=-72.4,2644. Although core polarization effects are absent, the v alence hfs results for U-235 I are in generally good agreement with ex periment and represent a modest improvement compared to existing semie mpirical values. An LS analysis is provided for the bound state.