More theoretical evidence for binding of a 6p electron in the lanthanide anions: Tm^-[Xe]4f¹³6s²6p¹

Recently, most of the lanthanide anions have been reported to be stable (Garwan et. al. (1990)) including Tm-. The authors present strong theoretical evidence, based on a Dirac-Hartree-Fock density functional theory (DHFDFT) study of the 70 electron system, that Tm- is stable in the electron configuration [Xe]4f136s26p1 and that it is not stable in the conventionally assumed [Xe]4f146s2 configuration, the ground state of Yb0. The EA of Tm- is estimated to be in the range 1 to 5 mHartrees. When this result is combined with previous predictions of a 6p electron being bound in Yb- (Vosko et. al. (1991)) and Lu- (Vosko and Chevary (1993)), it is natural to conjecture that the other lanthanides bind 6p electrons to form their stable anions.