DOI: 10.17188/1270943
title: Materials Data on K3NdSi7O17 by Materials Project

description: K3NdSi7O17 crystallizes in the trigonal P-3 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.78–3.28 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.96–3.18 Å. There are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded to six equivalent O2- atoms to form NdO6 octahedra that share corners with six equivalent SiO4 tetrahedra. All Nd–O bond lengths are 2.40 Å. In the second Nd3+ site, Nd3+ is bonded to six O2- atoms to form NdO6 octahedra that share corners with six SiO4 tetrahedra. There are four shorter (2.37 Å) and two longer (2.46 Å) Nd–O bond lengths. There are six 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 NdO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NdO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 34°. There are a spread of Si–O bond distances ranging from 1.58–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NdO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. 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 NdO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There is one shorter (1.61 Å) and three longer (1.66 Å) Si–O bond length. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.63 Å) Si–O bond length. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.62 Å) Si–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one Nd3+, 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 4-coordinate geometry to two equivalent K1+, one Nd3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one Nd3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Nd3+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a linear geometry to two Si4+ atoms.