Materials Data on Mg4As6Ir7 by Materials Project

Abstract

Mg4Ir7As6 crystallizes in the cubic Im-3m space group. The structure is three-dimensional. Mg is bonded to six equivalent Ir and six equivalent As atoms to form MgAs6Ir6 cuboctahedra that share corners with twelve equivalent MgAs6Ir6 cuboctahedra, corners with twelve equivalent IrMg4As4 cuboctahedra, edges with six equivalent IrMg4As4 cuboctahedra, faces with six equivalent MgAs6Ir6 cuboctahedra, and faces with two equivalent IrAs6 octahedra. All Mg–Ir bond lengths are 2.89 Å. All Mg–As bond lengths are 2.94 Å. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded to six equivalent As atoms to form IrAs6 octahedra that share corners with twenty-four equivalent IrMg4As4 cuboctahedra and faces with eight equivalent MgAs6Ir6 cuboctahedra. All Ir–As bond lengths are 2.57 Å. In the second Ir site, Ir is bonded to four equivalent Mg and four equivalent As atoms to form distorted IrMg4As4 cuboctahedra that share corners with eight equivalent MgAs6Ir6 cuboctahedra, corners with twelve equivalent IrMg4As4 cuboctahedra, corners with four equivalent IrAs6 octahedra, edges with two equivalent IrMg4As4 cuboctahedra, edges with four equivalent MgAs6Ir6 cuboctahedra, and faces with four equivalent IrMg4As4 cuboctahedra. The corner-sharing octahedral tilt angles are 53°. All Ir–As bond lengths are 2.55 Å. As is bonded in a 9-coordinate geometry to four equivalent Mg and five Ir atoms.