Materials Data on Eu3(MgSi)5 by Materials Project

Abstract

Eu3(MgSi)5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are five inequivalent Mg sites. In the first Mg site, Mg is bonded to four Si atoms to form MgSi4 tetrahedra that share corners with five MgSi4 tetrahedra and edges with four MgEuSi4 tetrahedra. There are a spread of Mg–Si bond distances ranging from 2.70–2.75 Å. In the second Mg site, Mg is bonded to one Eu and four Si atoms to form distorted MgEuSi4 tetrahedra that share corners with seven MgSi4 tetrahedra, edges with four MgEu2Si4 tetrahedra, and faces with two equivalent MgEu2Si4 tetrahedra. The Mg–Eu bond length is 3.27 Å. There are a spread of Mg–Si bond distances ranging from 2.71–2.78 Å. In the third Mg site, Mg is bonded to one Eu and four Si atoms to form distorted MgEuSi4 tetrahedra that share corners with nine MgEuSi4 tetrahedra, edges with two equivalent MgEuSi4 tetrahedra, and faces with two equivalent MgEu2Si4 tetrahedra. The Mg–Eu bond length is 3.27 Å. There are a spread of Mg–Si bond distances ranging from 2.66–2.77 Å. In the fourth Mg site, Mg is bonded to two equivalent Eu and four Si atoms to form distorted MgEu2Si4 tetrahedra that share corners with eight MgSi4 tetrahedra, edges with five MgEuSi4 tetrahedra, and faces with three MgEu2Si4 tetrahedra. Both Mg–Eu bond lengths are 3.31 Å. There are a spread of Mg–Si bond distances ranging from 2.73–2.78 Å. In the fifth Mg site, Mg is bonded to two equivalent Eu and four Si atoms to form distorted MgEu2Si4 tetrahedra that share corners with nine MgSi4 tetrahedra, edges with three MgEu2Si4 tetrahedra, and faces with three MgEuSi4 tetrahedra. Both Mg–Eu bond lengths are 3.24 Å. There are a spread of Mg–Si bond distances ranging from 2.73–2.82 Å. There are three inequivalent Eu sites. In the first Eu site, Eu is bonded in a 7-coordinate geometry to seven Si atoms. There are a spread of Eu–Si bond distances ranging from 3.25–3.38 Å. In the second Eu site, Eu is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Eu–Si bond distances ranging from 3.23–3.33 Å. In the third Eu site, Eu is bonded in a 6-coordinate geometry to six Mg and six Si atoms. There are a spread of Eu–Si bond distances ranging from 3.11–3.19 Å. There are five inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to four Mg, four Eu, and one Si atom. The Si–Si bond length is 2.38 Å. In the second Si site, Si is bonded in a 7-coordinate geometry to six Mg and one Eu atom. In the third Si site, Si is bonded in a 1-coordinate geometry to one Mg, six Eu, and two Si atoms. The Si–Si bond length is 2.41 Å. In the fourth Si site, Si is bonded in a 9-coordinate geometry to five Mg and four Eu atoms. In the fifth Si site, Si is bonded in a 9-coordinate geometry to four Mg, four Eu, and one Si atom.