Materials Data on K2Mn5Si12O31 by Materials Project

Abstract

K2Mn5Si12O31 crystallizes in the hexagonal P-62c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 12-coordinate geometry to twelve O2- atoms. All K–O bond lengths are 3.05 Å. In the second K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are three shorter (2.82 Å) and six longer (3.03 Å) K–O bond lengths. There are two inequivalent Mn+2.40+ sites. In the first Mn+2.40+ site, Mn+2.40+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SiO4 tetrahedra and edges with three equivalent MnO4 tetrahedra. There are three shorter (2.19 Å) and three longer (2.28 Å) Mn–O bond lengths. In the second Mn+2.40+ site, Mn+2.40+ is bonded to four O2- atoms to form distorted MnO4 tetrahedra that share corners with four SiO4 tetrahedra and edges with two equivalent MnO6 octahedra. There are two shorter (2.06 Å) and two longer (2.10 Å) Mn–O bond lengths. There are two 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 MnO6 octahedra, a cornercorner with one MnO4 tetrahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There is one shorter (1.62 Å) and three longer (1.64 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 MnO6 octahedra, a cornercorner with one MnO4 tetrahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 9-coordinate geometry to nine O2- atoms. There are three shorter (2.85 Å) and six longer (3.09 Å) O–O bond lengths. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent Si4+ and one O2- atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two Mn+2.40+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two Mn+2.40+, one Si4+, and one O2- atom.