Rigidity of Orientationally Ordered Domains of Short Chain Molecules
  By molecular dynamics simulation, discovered is a strange rigid-like nature for a hexagonally packed domain of short chain molecules. In spite of the non-bonded short-range interaction potential (Lennard-Jones potential) among chain molecules, the packed domain gives rise to a resultant global moment of inertia. Accordingly, as two domains encounter obliquely, they rotate so as to be parallel to each other keeping their overall structures as if they were rigid bodies. 
Hiroaki Nakamura, Susumu Fujiwara, Tetsuya Sato