Materials Data on Na5Tb4Si4O16F by Materials Project

Abstract

Na5Tb4Si4O16F crystallizes in the tetragonal I-4 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.38–2.85 Å. In the second Na1+ site, Na1+ is bonded in a distorted q6 geometry to eight O2- and two equivalent F1- atoms. There are four shorter (2.62 Å) and four longer (2.82 Å) Na–O bond lengths. Both Na–F bond lengths are 2.73 Å. Tb3+ is bonded in a 8-coordinate geometry to seven O2- and one F1- atom. There are a spread of Tb–O bond distances ranging from 2.29–2.57 Å. The Tb–F bond length is 2.55 Å. Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, two equivalent Tb3+, one Si4+, and one F1- atom. The O–F bond length is 2.78 Å. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two equivalent Tb3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Na1+, one Tb3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, two equivalent Tb3+, one Si4+, and one F1- atom. The O–F bond length is 2.70 Å. F1- is bonded in a 6-coordinate geometry to two equivalent Na1+, four equivalent Tb3+, and eight O2- atoms.