DOE OSTI2020
NaY2F7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.19–2.84 Å. There are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to eight F1- atoms to form a mixture of distorted corner and edge-sharing YF8 hexagonal bipyramids. There are a spread of Y–F bond distances ranging from 2.19–2.53 Å. In the second Y3+ site, Y3+ is bonded to eight F1- atoms to form a mixture of distorted corner and edge-sharing YF8 hexagonal bipyramids. There are a spread of Y–F bond distances ranging from 2.19–2.53 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to three equivalent Y3+ atoms. In the second F1- site, F1- is bonded in a 4-coordinate geometry to one Na1+ and three equivalent Y3+ atoms. In the third F1- site, F1- is bonded in a linear geometry to two Y3+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to three equivalent Y3+ atoms. In the fifth F1- site, F1- is bonded in a 4-coordinate geometry to three equivalent Na1+ and one Y3+ atom. In the sixth F1- site, F1- is bonded in a 4-coordinate geometry to three equivalent Na1+ and one Y3+ atom. In the seventh F1- site, F1- is bonded in a 4-coordinate geometry to one Na1+ and three equivalent Y3+ atoms.