SC — MEH — MO calculations on lanthanide systems. II. Sm(Cp*) + , Sm(Cp*) 2+ , and the [Sm(Cp*)] 4 8+ tetrameter

SC – MEH – MO calculations with quasi‐relativistic STOS , electron repulsion correlation, and configuration interaction ( QR – SCMEH – RCCI ) have been extended from the Sm(Cp*) 2 results initially reported to the ions Sm(Cp*) + , Sm(Cp*) 2+ , and the unique tetrameter [Sm(Cp*)]   4 8+ . The latter was synthesized and its structure characterized, with the Sm atoms bridged by N 2 H   2 2− , N 2 H   3 − , and NH 3 groups. The initial calculations have omitted the bridging lipnds, so as to test the possibility of Sm–Sm bonding since the distances are some 3.55 Å (about 0.05 Å shorter than in Sm metal). © 1995 John Wiley & Sons, Inc.