Materials Data on Mg15Si2Ir5 by Materials Project

Abstract

Mg15Ir5Si2 crystallizes in the tetragonal P4_2/n space group. The structure is three-dimensional. there are eight inequivalent Mg sites. In the first Mg site, Mg is bonded in a 2-coordinate geometry to three Ir and one Si atom. There are a spread of Mg–Ir bond distances ranging from 2.71–3.01 Å. The Mg–Si bond length is 2.78 Å. In the second Mg site, Mg is bonded in a distorted bent 150 degrees geometry to two Ir atoms. There are one shorter (2.63 Å) and one longer (2.66 Å) Mg–Ir bond lengths. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Ir atoms. There are one shorter (2.82 Å) and one longer (3.00 Å) Mg–Ir bond lengths. In the fourth Mg site, Mg is bonded in a 1-coordinate geometry to three Ir and one Si atom. There are a spread of Mg–Ir bond distances ranging from 2.71–2.83 Å. The Mg–Si bond length is 2.79 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to three Ir atoms. There are a spread of Mg–Ir bond distances ranging from 2.69–2.89 Å. In the sixth Mg site, Mg is bonded in a 6-coordinate geometry to four Ir and two equivalent Si atoms. There are a spread of Mg–Ir bond distances ranging from 2.80–3.04 Å. There are one shorter (2.79 Å) and one longer (2.80 Å) Mg–Si bond lengths. In the seventh Mg site, Mg is bonded in a 6-coordinate geometry to four Ir and two equivalent Si atoms. There are a spread of Mg–Ir bond distances ranging from 2.77–3.03 Å. There are one shorter (2.77 Å) and one longer (2.82 Å) Mg–Si bond lengths. In the eighth Mg site, Mg is bonded in a linear geometry to two equivalent Ir atoms. Both Mg–Ir bond lengths are 2.70 Å. There are three inequivalent Ir sites. In the first Ir site, Ir is bonded in a 9-coordinate geometry to eight Mg and one Si atom. The Ir–Si bond length is 2.36 Å. In the second Ir site, Ir is bonded in a 10-coordinate geometry to nine Mg and one Si atom. The Ir–Si bond length is 2.36 Å. In the third Ir site, Ir is bonded to ten Mg and two equivalent Si atoms to form distorted face-sharing IrMg10Si2 cuboctahedra. Both Ir–Si bond lengths are 2.38 Å. Si is bonded in a 9-coordinate geometry to six Mg and three Ir atoms.