Materials Data on CsScAsO4F by Materials Project
CsScAsO4F crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 12-coordinate geometry to eight O2- and two F1- atoms. There are a spread of Cs–O bond distances ranging from 2.98–3.73 Å. There are one shorter (3.04 Å) and one longer (3.64 Å) Cs–F bond lengths. In the second Cs1+ site, Cs1+ is bonded in a 3-coordinate geometry to two O2- and one F1- atom. There are one shorter (2.94 Å) and one longer (2.98 Å) Cs–O bond lengths. The Cs–F bond length is 2.99 Å. There are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to three O2- and two F1- atoms to form distorted ScO3F2 trigonal bipyramids that share a cornercorner with one ScO4F2 octahedra, a cornercorner with one AsO5 trigonal bipyramid, and an edgeedge with one ScO4F2 octahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Sc–O bond distances ranging from 1.93–2.11 Å. There are one shorter (2.05 Å) and one longer (2.25 Å) Sc–F bond lengths. In the second Sc3+ site, Sc3+ is bonded to four O2- and two F1- atoms to form distorted ScO4F2 octahedra that share a cornercorner with one ScO3F2 trigonal bipyramid, corners with two equivalent AsO5 trigonal bipyramids, and an edgeedge with one ScO3F2 trigonal bipyramid. There are a spread of Sc–O bond distances ranging from 1.93–2.30 Å. There are one shorter (2.05 Å) and one longer (2.30 Å) Sc–F bond lengths. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.80–1.91 Å. In the second As5+ site, As5+ is bonded to five O2- atoms to form distorted AsO5 trigonal bipyramids that share corners with two equivalent ScO4F2 octahedra and a cornercorner with one ScO3F2 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 36–54°. There are a spread of As–O bond distances ranging from 1.67–2.25 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+ and two As5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Sc3+ and two As5+ atoms. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Sc3+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Cs1+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Cs1+ and one Sc3+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Cs1+ and one Sc3+ atom. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to two Cs1+ and two Sc3+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Cs1+, one Sc3+, and two As5+ atoms. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to one Cs1+ and two Sc3+ atoms. In the second F1- site, F1- is bonded in a 2-coordinate geometry to two Cs1+ and two Sc3+ atoms.