  The structure of driven three-dimensional complex plasma clusters was studied
experimentally. The clusters consisted of around 60 hollow glass spheres with a
diameter of 22 microns that were suspended in a plasma of rf discharge in
argon. The particles were confined in a glass box with conductive yet
transparent coating on its four side walls, this allowed to manipulate the
particle cluster by biasing the confining walls in a certain sequence. In this
work, a rotating electric field was used to drive the clusters. Depending on
the excitation frequency, the clusters rotated (10^4 - 10^7 times slower than
the rotating field) or remained stationary. The cluster structure was neither
that of nested spherical shells nor simple chain structure. Strings of various
lengths were found consisting of 2 to 5 particles, their spatial and temporal
correlations were studied. The results are compared to recent simulations.
