Materials Data on K4In2Si8O21 by Materials Project
K4In2Si8O21 crystallizes in the monoclinic P2_1/c 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 2.79–3.34 Å. In the second 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 2.70–3.31 Å. In3+ is bonded to five O2- atoms to form distorted InO5 trigonal bipyramids that share corners with five SiO4 tetrahedra. There are a spread of In–O bond distances ranging from 2.09–2.18 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 SiO4 tetrahedra and a cornercorner with one InO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra and a cornercorner with one InO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two SiO4 tetrahedra and corners with two equivalent InO5 trigonal bipyramids. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three SiO4 tetrahedra and a cornercorner with one InO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, one In3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a linear geometry to two equivalent K1+ and two equivalent Si4+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one In3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Si4+ atoms.