DOE OSTI2019
Ca2Y3Si3O13 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.89 Å. In the second Ca site, Ca is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of Ca–O bond distances ranging from 2.38–2.93 Å. There are three inequivalent Y sites. In the first Y site, Y is bonded to seven O atoms to form distorted YO7 pentagonal bipyramids that share corners with six YO7 pentagonal bipyramids, corners with four SiO4 tetrahedra, and an edgeedge with one SiO4 tetrahedra. There are a spread of Y–O bond distances ranging from 2.31–2.54 Å. In the second Y site, Y is bonded to seven O atoms to form distorted YO7 pentagonal bipyramids that share corners with six YO7 pentagonal bipyramids, corners with four SiO4 tetrahedra, and an edgeedge with one SiO4 tetrahedra. There are a spread of Y–O bond distances ranging from 2.30–2.52 Å. In the third Y site, Y is bonded to seven O atoms to form distorted YO7 pentagonal bipyramids that share corners with six YO7 pentagonal bipyramids, corners with four SiO4 tetrahedra, and an edgeedge with one SiO4 tetrahedra. There are a spread of Y–O bond distances ranging from 2.30–2.53 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four YO7 pentagonal bipyramids and an edgeedge with one YO7 pentagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four YO7 pentagonal bipyramids and an edgeedge with one YO7 pentagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four YO7 pentagonal bipyramids and an edgeedge with one YO7 pentagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. There are thirteen inequivalent O sites. In the first O site, O is bonded to two Ca, one Y, and one Si atom to form distorted edge-sharing OCa2YSi tetrahedra. In the second O site, O is bonded in a 4-coordinate geometry to two Ca, one Y, and one Si atom. In the third O site, O is bonded in a 4-coordinate geometry to two Ca, one Y, and one Si atom. In the fourth O site, O is bonded to two Ca, one Y, and one Si atom to form distorted edge-sharing OCa2YSi tetrahedra. In the fifth O site, O is bonded in a 4-coordinate geometry to two Ca, one Y, and one Si atom. In the sixth O site, O is bonded to two Ca, one Y, and one Si atom to form distorted edge-sharing OCa2YSi tetrahedra. In the seventh O site, O is bonded in a 1-coordinate geometry to one Ca, two Y, and one Si atom. In the eighth O site, O is bonded in a 1-coordinate geometry to one Ca, two Y, and one Si atom. In the ninth O site, O is bonded in a 1-coordinate geometry to one Ca, two Y, and one Si atom. In the tenth O site, O is bonded in a 1-coordinate geometry to one Ca, two Y, and one Si atom. In the eleventh O site, O is bonded in a 1-coordinate geometry to one Ca, two Y, and one Si atom. In the twelfth O site, O is bonded in a 1-coordinate geometry to one Ca, two Y, and one Si atom. In the thirteenth O site, O is bonded in a trigonal planar geometry to three Y atoms.