(color online) Frustration in polytetrahedra in Euclidean d = 3. (a) The pentagonal bipyramid “7A” is constructed with five tetrahedra (b) which leads to a gap of . (c) 13-membered icosahedron. (d) Icosahedra have bonds between particles in the shell stretched by 5% with respect to the bonds between the central particle and the shell particles.[25]