  The Ricci curvature criterion is used for the investigation of the relative
instability of several configurations of N-body gravitating systems. It is
shown, that the systems with double massive centers are more unstable than the
homogeneous systems and those with one massive center. In general this shows
the efficiency of the Ricci curvature method introduced by Gurzadyan and
Kocharyan (1987) for the study of N-body systems via relatively simple
calculations, i.e. for small N, and hence small computer resources.
