  All possible non-isomorphic arrangements of 12 spheres kissing a central
sphere (the Gregory-Newton problem) are obtained for the sticky-hard-sphere
(SHS) model, and subsequently projected by geometry optimization onto a set of
structures derived from an attractive Lennard-Jones (LJ) type of potential. It
is shown that all 737 derived SHS contact graphs corresponding to the 12 outer
spheres are (edge-induced) subgraphs of the icosahedral graph. The most widely
used LJ(6,12) potential has only one minimum structure corresponding to the
ideal icosahedron where the 12 outer spheres do not touch each other. The point
of symmetry breaking away from the icosahedral symmetry towards the SHS limit
is obtained for general LJ($a,b$) potentials with exponents $a,b\in
\mathbb{R}_+$. Only if the potential becomes very repulsive in the short-range,
determined by the LJ hard-sphere radius $\sigma$, symmetry broken solutions are
observed.
