We extend a recent billiard model of a self-bound N-body Hamiltonian to con
sider a finite two-body interaction. This permits a treatment of the Hamilt
onian by a mean field theory. The density and the mean field potential can
be accurately described by a scaling function which shows the qualitative f
eatures of the Liquid drop picture of the nucleus. (C) 2000 Elsevier Scienc
e B.V. All rights reserved.