Materials Data on LaY9Si8 by Materials Project

LaY9Si8 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. La is bonded in a 7-coordinate geometry to seven Si atoms. There are a spread of La–Si bond distances ranging from 3.10–3.62 Å. There are nine inequivalent Y sites. In the first Y site, Y is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Y–Si bond distances ranging from 2.88–3.02 Å. In the second Y site, Y is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Y–Si bond distances ranging from 2.85–3.03 Å. In the third Y site, Y is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Y–Si bond distances ranging from 2.89–3.03 Å. In the fourth Y site, Y is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Y–Si bond distances ranging from 2.89–3.04 Å. In the fifth Y site, Y is bonded to six Si atoms to form a mixture of distorted face and corner-sharing YSi6 octahedra. The corner-sharing octahedra tilt angles range from 55–56°. There are a spread of Y–Si bond distances ranging from 2.93–3.31 Å. In the sixth Y site, Y is bonded to six Si atoms to form a mixture of distorted face and corner-sharing YSi6 octahedra. The corner-sharing octahedra tilt angles range from 55–56°. There are a spread of Y–Si bond distances ranging from 2.96–3.26 Å. In the seventh Y site, Y is bonded in a 6-coordinate geometry to seven Si atoms. There are a spread of Y–Si bond distances ranging from 3.05–3.68 Å. In the eighth Y site, Y is bonded to six Si atoms to form a mixture of distorted face and corner-sharing YSi6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 43–44°. There are a spread of Y–Si bond distances ranging from 3.03–3.15 Å. In the ninth Y site, Y is bonded to six Si atoms to form a mixture of distorted face and corner-sharing YSi6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 44°. There are a spread of Y–Si bond distances ranging from 3.09–3.18 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to eight Y and one Si atom. The Si–Si bond length is 2.54 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to two equivalent La, six Y, and one Si atom. The Si–Si bond length is 2.55 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to eight Y and one Si atom. In the fourth Si site, Si is bonded in a 9-coordinate geometry to one La, seven Y, and one Si atom. In the fifth Si site, Si is bonded in a 9-coordinate geometry to one La, seven Y, and one Si atom. The Si–Si bond length is 2.50 Å. In the sixth Si site, Si is bonded in a 9-coordinate geometry to one La, seven Y, and one Si atom. The Si–Si bond length is 2.53 Å. In the seventh Si site, Si is bonded in a 8-coordinate geometry to one La, six Y, and one Si atom. In the eighth Si site, Si is bonded in a 8-coordinate geometry to one La, six Y, and one Si atom.