  Analytical relationships for the surface and curvature energies of oblate and
prolate semi-spheroidal atomic clusters have been obtained. By modifying the
cluster shape from a spheroid to a semi-spheroid the most stable shape was
changed from a sphere to a superdeformed prolate semi-spheroid (including the
flat surface of the end cap). Potential energy surfaces vs. deformation and the
number of atoms, N, illustrate this property independent of N.
