Materials Data on K2EuSi4O10F by Materials Project
K2EuSi4O10F crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to five O2- and one F1- atom. There are a spread of K–O bond distances ranging from 2.86–3.00 Å. The K–F bond length is 2.97 Å. In the second 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 2.86–3.36 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to six O2- and one F1- atom. There are a spread of K–O bond distances ranging from 2.88–3.26 Å. The K–F bond length is 2.86 Å. In the fourth K1+ site, K1+ is bonded in a 7-coordinate geometry to six O2- and one F1- atom. There are a spread of K–O bond distances ranging from 2.91–3.19 Å. The K–F bond length is 2.81 Å. Eu3+ is bonded to four O2- and two F1- atoms to form EuO4F2 octahedra that share corners with two equivalent EuO4F2 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–41°. There are a spread of Eu–O bond distances ranging from 2.29–2.33 Å. There are one shorter (2.27 Å) and one longer (2.31 Å) Eu–F bond lengths. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one EuO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There is one shorter (1.60 Å) and three longer (1.66 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one EuO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one EuO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 9°. There are a spread of Si–O bond distances ranging from 1.59–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one EuO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 42°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one Eu3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Eu3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, one Eu3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to one K1+, one Eu3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two equivalent Si4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two equivalent Si4+ atoms. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to one K1+ and two equivalent Eu3+ atoms. In the second F1- site, F1- is bonded in a 4-coordinate geometry to two K1+ and two equivalent Eu3+ atoms.