Materials Data on K2ScSi4O10F by Materials Project

Abstract

K2ScSi4O10F crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to seven O2- and one F1- atom. There are a spread of K–O bond distances ranging from 2.84–2.99 Å. The K–F bond length is 2.95 Å. Sc3+ is bonded to four equivalent O2- and two F1- atoms to form ScO4F2 octahedra that share corners with two equivalent ScO4F2 octahedra and corners with four equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. All Sc–O bond lengths are 2.09 Å. There are one shorter (2.03 Å) and one longer (2.11 Å) Sc–F bond lengths. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ScO4F2 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 27°. There are a spread of Si–O bond distances ranging from 1.59–1.66 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+, one Sc3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Si4+ atoms. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a linear geometry to two equivalent Sc3+ atoms. In the second F1- site, F1- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent Sc3+ atoms.