  A combinatorial model of molecular conformational space that was previously
developped (J. Gabarro-Arpa, Comp. Biol. and Chem. 27, (2003) 153-159), had the
drawback that structures could not be properly embedded beacause it lacked
explicit rotational symmetry. The problem can be circumvented by sorting the
elementary 3D components of a molecular system into a finite set of classes
that can be separately embedded. This also opens up the possibility of encoding
the dynamical states into a graph structure.
