Overlapping Unit Cells in 3d Quasicrystal Structure
  A 3-dimensional quasiperiodic lattice, with overlapping unit cells and periodic in one direction, is constructed using grid and projection methods pioneered by de Bruijn. Each unit cell consists of 26 points, of which 22 are the vertices of a convex polytope P, and 4 are interior points also shared with other neighboring unit cells. Using Kronecker's theorem the frequencies of all possible types of overlapping are found. 
Helen Au-Yang and Jacques H.H. Perk (Oklahoma State University)