VERY HIGHLY EXCITED BOUND-STATES OF ATOMIC NEGATIVE-IONS HAVING ALL THEIR ELECTRONS WITH UNPAIRED SPINS

By identifying a special class of atomic negative ion states where all electron spins are unpaired and where the nuclear charge is partially unscreened, we predict, via large-scale state-specific calculations, that B-, C-, N- and O- have states which belong to the discrete spectr um even though they are very highly excited and embedded in a multitud e of ionization thresholds. For example, the O- 1s2s2p(3)3s3p(3 10)S s tate lies 600.6 eV above the O 1s(2)2s(2)2p(4 3)P ground state and yet it is bound. For N-, the two maximum spin states, 1s2s2p(3)3s3p(2) P- 9(0) and 1s2s2p(3)3p(3) S-9, are connected by an electric dipole trans ition with lambda = 4615.5 Angstrom and with transition rate similar t o 2.7 x 10(8) s(-1). For these unique states, the reliable prediction of the relevant energy differences demanded the execution of systemati c all-electron calculations, with inter- and intra-shell correlations included.