Intermetallic compounds: antimony–beryllium SbBe₁₃

Dense Sphere Packing in the NaZn13 Structure Type

“…Indeed the wide range over which this ternary exceeds the other known packing options helps to explain the occurrence of the NaZn 13 structure in other colloidal crystals at radius ratios outside the previously predicted ranges. 4,28 Genuine ternary nanoparticle superlattices (with size ratios quite different to that required for the optimal A 12 BC structure) have recently been observed to form a structure with the AlMgB 4 structure type at a packing fraction of only Circles: naturally occurring atomic structures, filled if the icosahedral atom is beryllium [18][19][20][21][22][23][24][25] otherwise open. 1,26,27 Zintl parameters, 1 originally for NaZn 13 were adopted in early work as consistent with the diffraction pattern of a number of other compounds, LaCo 13 , EuZn 13 , ZrBe 13 , HfBe 13 , but the degree of uncertainty is unclear.…”

“…Figure 4 is a parameter plot showing all the structures identified in this paper, in comparison to the experimentally determined y and z parameters of binary atomic structures with the NaZn 13 structure type. 1,[18][19][20][21][22][23][24][25][26][27] Of all the geometric predictors, the constrained optimal ternary packing lines are clearly the best description of the atomic structures, in particular those involving beryllium. Indeed, many of these XBe 13 structures are clustered around the optimal ternary structure, the regular snub cube.…”

“…Filled red square: A particles form a regular snub cube around the B particles. Circles: naturally occurring atomic structures, filled if the icosahedral atom is beryllium – otherwise open. ,, Zintl parameters, originally for NaZn 13 were adopted in early work as consistent with the diffraction pattern of a number of other compounds, LaCo 13 , EuZn 13 , ZrBe 13 , HfBe 13 , but the degree of uncertainty is unclear.…”