The (6-1) structure can be understood as a clathrate structure. The structural data of the (6-1) structure at several radius ratios: 0.264, 0.267, 0.270, 0.273, 0.275, 0.278, 0.281, 0.284, 0.287, 0.289, 0.292, 0.295,
0.298, 0.301, 0.304, 0.307, 0.309, 0.312, 0.315, 0.318, 0.321, 0.324, 0.326, 0.329, 0.332, 0.335, 0.338, 0.341, 0.343, 0.346, 0.349, and 0.352, are downloadable