Materials Data on Ce4Mg7Ge6 by Materials Project

Abstract

Mg7Ce4Ge6 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 4-coordinate geometry to four Ge atoms. There are a spread of Mg–Ge bond distances ranging from 2.72–2.98 Å. In the second Mg site, Mg is bonded to four Ge atoms to form distorted MgGe4 tetrahedra that share corners with two equivalent CeGe6 octahedra, corners with six MgGe4 tetrahedra, edges with two equivalent CeGe6 octahedra, and an edgeedge with one MgGe4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Mg–Ge bond distances ranging from 2.80–2.88 Å. In the third Mg site, Mg is bonded to four Ge atoms to form distorted MgGe4 tetrahedra that share corners with three equivalent CeGe6 octahedra, corners with six MgGe4 tetrahedra, and edges with three equivalent CeGe6 octahedra. The corner-sharing octahedra tilt angles range from 14–62°. There are a spread of Mg–Ge bond distances ranging from 2.67–2.94 Å. In the fourth Mg site, Mg is bonded in a 4-coordinate geometry to four equivalent Ge atoms. All Mg–Ge bond lengths are 2.97 Å. There are two inequivalent Ce sites. In the first Ce site, Ce is bonded in a 5-coordinate geometry to five Ge atoms. There are two shorter (3.17 Å) and three longer (3.21 Å) Ce–Ge bond lengths. In the second Ce site, Ce is bonded to six Ge atoms to form distorted CeGe6 octahedra that share corners with five MgGe4 tetrahedra, edges with four equivalent CeGe6 octahedra, and edges with five MgGe4 tetrahedra. There are a spread of Ce–Ge bond distances ranging from 3.14–3.38 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to five Mg and four Ce atoms. In the second Ge site, Ge is bonded in a 7-coordinate geometry to four Mg and three equivalent Ce atoms. In the third Ge site, Ge is bonded in a 9-coordinate geometry to five Mg and four Ce atoms.