Materials Data on K5Y2Si4O13F by Materials Project
K5Y2FSi4O13 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are five inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 12-coordinate geometry to ten O2- and two equivalent F1- atoms. There are a spread of K–O bond distances ranging from 3.00–3.39 Å. Both K–F bond lengths are 2.92 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to eight O2- and one F1- atom. There are a spread of K–O bond distances ranging from 2.77–3.33 Å. The K–F bond length is 2.69 Å. In the third K1+ site, K1+ is bonded in a 9-coordinate geometry to eight O2- and one F1- atom. There are a spread of K–O bond distances ranging from 2.86–3.07 Å. The K–F bond length is 2.67 Å. In the fourth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.93–3.28 Å. In the fifth K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.82–3.45 Å. There are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to five O2- and one F1- atom to form YO5F octahedra that share a cornercorner with one YO5F octahedra and corners with five SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 2°. There are two shorter (2.21 Å) and three longer (2.24 Å) Y–O bond lengths. The Y–F bond length is 2.58 Å. In the second Y3+ site, Y3+ is bonded to five O2- and one F1- atom to form YO5F octahedra that share a cornercorner with one YO5F octahedra and corners with five SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Y–O bond distances ranging from 2.20–2.27 Å. The Y–F bond length is 2.51 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent YO5F octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–49°. There are a spread of Si–O bond distances ranging from 1.63–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent YO5F octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 17°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent YO5F octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 23°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent YO5F octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 11–24°. There is three shorter (1.64 Å) and one longer (1.69 Å) Si–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Y3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three equivalent K1+, one Y3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three K1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Y3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to three K1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Y3+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to four K1+, one Y3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent K1+, one Y3+, and one Si4+ atom. F1- is bonded to four K1+ and two Y3+ atoms to form corner-sharing FK4Y2 octahedra. The corner-sharing octahedral tilt angles are 6°.