Materials Data on Ca3Al2S(OF)8 by Materials Project
Ca3Al2S(OF)8 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 8-coordinate geometry to three O and five F atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.79 Å. There are a spread of Ca–F bond distances ranging from 2.32–2.54 Å. In the second Ca site, Ca is bonded in a 4-coordinate geometry to four O and four F atoms. There are two shorter (2.56 Å) and two longer (2.73 Å) Ca–O bond lengths. There are two shorter (2.24 Å) and two longer (2.33 Å) Ca–F bond lengths. Al is bonded to two equivalent O and four F atoms to form edge-sharing AlO2F4 octahedra. There is one shorter (1.87 Å) and one longer (1.88 Å) Al–O bond length. There are a spread of Al–F bond distances ranging from 1.74–1.87 Å. S is bonded in a tetrahedral geometry to four O atoms. There is two shorter (1.48 Å) and two longer (1.52 Å) S–O bond length. There are four inequivalent O sites. In the first O site, O is bonded in a 2-coordinate geometry to one Ca, two equivalent Al, and one O atom. The O–O bond length is 1.60 Å. In the second O site, O is bonded in a water-like geometry to two Ca atoms. In the third O site, O is bonded in a 3-coordinate geometry to two Ca and one S atom. In the fourth O site, O is bonded in a single-bond geometry to one S atom. There are four inequivalent F sites. In the first F site, F is bonded in a 1-coordinate geometry to two equivalent Ca and one Al atom. In the second F site, F is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca and one Al atom. In the third F site, F is bonded in a bent 150 degrees geometry to one Ca and one Al atom. In the fourth F site, F is bonded in a distorted trigonal planar geometry to two Ca and one Al atom.