  We have studied the ground state of a simple cubic magnetic cluster, which
contains a spin s at each corner site. The ground state of such cluster depends
on the competition between nearest, next-nearest and next-next-nearest-neighbor
exchange interactions. We have calculated the "phase" diagrams for the Izing
clusters with s=1/2;1;3/2;5/2;\infty and for the Heisenberg clusters with s=1/2
and s=1. We have found that the "phase" diagram is remarkably independent on
the s value. It is important also that the Izing "phase" diagram can be used as
a rough approximation for the Heisenberg model.
