Materials Data on Ba2Na2SrAl4F20 by Materials Project
Na2Ba2SrAl4F20 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na1+ is bonded in a 4-coordinate geometry to nine F1- atoms. There are a spread of Na–F bond distances ranging from 2.17–2.98 Å. Ba2+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Ba–F bond distances ranging from 2.70–3.04 Å. Sr2+ is bonded in a 10-coordinate geometry to six F1- atoms. There are a spread of Sr–F bond distances ranging from 2.52–2.56 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles are 31°. There are a spread of Al–F bond distances ranging from 1.81–1.88 Å. In the second Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles are 31°. There are a spread of Al–F bond distances ranging from 1.79–1.88 Å. There are ten inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted linear geometry to one Na1+ and one Al3+ atom. In the second F1- site, F1- is bonded in a 1-coordinate geometry to one Na1+, one Ba2+, one Sr2+, and one Al3+ atom. In the third F1- site, F1- is bonded in a distorted single-bond geometry to one Na1+, one Ba2+, one Sr2+, and one Al3+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one Al3+ atom. In the fifth F1- site, F1- is bonded in a 1-coordinate geometry to two equivalent Na1+, one Sr2+, and one Al3+ atom. In the sixth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Na1+ and two Al3+ atoms. In the seventh F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one Al3+ atom. In the eighth F1- site, F1- is bonded in a bent 150 degrees geometry to one Na1+ and two Al3+ atoms. In the ninth F1- site, F1- is bonded in a 4-coordinate geometry to one Na1+, two equivalent Ba2+, and one Al3+ atom. In the tenth F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, two equivalent Ba2+, and one Al3+ atom.