Materials Data on K5Pr4Si4O16F by Materials Project

Abstract

K5Pr4Si4O16F crystallizes in the tetragonal I-4 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first 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 2.59–2.94 Å. In the second K1+ site, K1+ is bonded in a distorted q6 geometry to eight O2- and two equivalent F1- atoms. There are four shorter (2.88 Å) and four longer (2.95 Å) K–O bond lengths. Both K–F bond lengths are 2.79 Å. Pr3+ is bonded in a 8-coordinate geometry to seven O2- and one F1- atom. There are a spread of Pr–O bond distances ranging from 2.45–2.64 Å. The Pr–F bond length is 2.74 Å. Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, two equivalent Pr3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, two equivalent Pr3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to four equivalent K1+, one Pr3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, two equivalent Pr3+, and one Si4+ atom. F1- is bonded to two equivalent K1+ and four equivalent Pr3+ atoms to form distorted corner-sharing FK2Pr4 octahedra. The corner-sharing octahedral tilt angles are 0°.