Materials Data on CaAl(OF2)2 by Materials Project
CaAl(OF2)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ca is bonded in a 8-coordinate geometry to two equivalent O and six F atoms. There are one shorter (2.53 Å) and one longer (2.57 Å) Ca–O bond lengths. There are a spread of Ca–F bond distances ranging from 2.29–2.66 Å. Al is bonded to two equivalent O and four F atoms to form distorted edge-sharing AlO2F4 octahedra. There is one shorter (1.98 Å) and one longer (2.00 Å) Al–O bond length. There are a spread of Al–F bond distances ranging from 1.73–1.85 Å. There are two inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two equivalent Ca atoms. In the second O site, O is bonded in a 3-coordinate geometry to two equivalent Al and one O atom. The O–O bond length is 1.46 Å. There are four inequivalent F sites. In the first F site, F is bonded in a bent 150 degrees geometry to one Ca and one Al atom. In the second F site, F is bonded in a distorted bent 150 degrees geometry to one Ca and one Al atom. In the third F site, F is bonded in a 2-coordinate geometry to two equivalent Ca and one Al atom. In the fourth F site, F is bonded in a distorted trigonal planar geometry to two equivalent Ca and one Al atom.