Evidence of electronic shell structure in Cs-O clusters

Abstract
Unusually high ionization energies have been observed for Cs-O clusters having certain sizes and composition, namely for Cs2n+z On with z=8, 18, 34, 58, and 92. The anomalies are well defined for clusters containing from 1 to 7 oxygen atoms. The indicated values of z are identical to the number of electrons in closed shells of angular momentum.