Self-assembly of a space-tessellating structure in the binary system of   hard tetrahedra and octahedra
  We report the formation of a binary crystal of hard polyhedra due solely to entropic forces. Although the alternating arrangement of octahedra and tetrahedra is a known space-tessellation, it had not previously been observed in self-assembly simulations. Both known one-component phases - the dodecagonal quasicrystal of tetrahedra and the densest-packing of octahedra in the Minkowski lattice - are found to coexist with the binary phase. No additional crystalline phases were observed. 
Andrew T. Cadotte, Julia Dshemuchadse, Pablo F. Damasceno, Richmond S.   Newman, and Sharon C. Glotzer
cond-mat.soft