Materials Data on CaSi7Ir3 by Materials Project
CaIr3Si7 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. Ca2+ is bonded to twelve equivalent Si+1.71- atoms to form edge-sharing CaSi12 cuboctahedra. There are six shorter (3.14 Å) and six longer (3.19 Å) Ca–Si bond lengths. Ir+3.33+ is bonded in a 7-coordinate geometry to seven Si+1.71- atoms. There are a spread of Ir–Si bond distances ranging from 2.45–2.54 Å. There are two inequivalent Si+1.71- sites. In the first Si+1.71- site, Si+1.71- is bonded in a trigonal planar geometry to three equivalent Ir+3.33+ atoms. In the second Si+1.71- site, Si+1.71- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and three equivalent Ir+3.33+ atoms.
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