Clusters of the Ta network in hP386-Al57.4Cu3.6Ta39.0. On the top, the second cluster shells around 2a and 2c are shown in blue and red. In the top middle a pentagonal Ta-bifrustum and its inner pentagonal bipyramid (purple) are depicted. The arrangement of these bifrusta around 2a and 2c positions is shown below and at the far left the F1628 polyhedron (green) is shown with hexagonal bipyramids (yellow) on three of its four hexagonal faces. The packing of all these polyhedra is shown in the lower right.