encapsulated in Si clusters reveals that Cr Si 12 is more stable than its neighbors. The origin
of this enhanced stability is consistent with the 18-electron sum rule commonly used in the
synthesis of stable chemical complexes, and may provide a criterion for a systematic search
of magic numbers in metalloinorganic clusters. The 6 μ B magnetic moment of the caged Cr
atom, the largest among the 3 d transition metal atoms, is completely quenched. This effect …