  An analysis of the structural properties of three-dimensional Coulomb
clusters confined in a spherical parabolic trap is presented. Based on
extensive high accuracy computer simulations the shell configurations and
energies for particle numbers in the range $60 \le N\le 160$ are reported.
Further, the intrashell symmetry and the lowest metastable configurations are
analyzed for small clusters and a novel type of excited state which does not
involve a change of shell configuration is identified.
