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DOE OSTI · 1300728

Materials Data on Sr2CaI6 by Materials Project

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Abstract

Sr2CaI6 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to seven I1- atoms. There are a spread of Sr–I bond distances ranging from 3.29–3.99 Å. In the second Sr2+ site, Sr2+ is bonded to seven I1- atoms to form distorted SrI7 pentagonal bipyramids that share corners with five equivalent CaI6 octahedra, an edgeedge with one CaI6 octahedra, and an edgeedge with one SrI7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 35–60°. There are a spread of Sr–I bond distances ranging from 3.32–3.66 Å. Ca2+ is bonded to six I1- atoms to form CaI6 octahedra that share corners with five equivalent SrI7 pentagonal bipyramids, an edgeedge with one CaI6 octahedra, and an edgeedge with one SrI7 pentagonal bipyramid. There are a spread of Ca–I bond distances ranging from 3.12–3.27 Å. There are six inequivalent I1- sites. In the first I1- site, I1- is bonded to three Sr2+ and one Ca2+ atom to form distorted corner-sharing ISr3Ca tetrahedra. In the second I1- site, I1- is bonded in a 3-coordinate geometry to three Sr2+ and one Ca2+ atom. In the third I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to one Sr2+ and two equivalent Ca2+ atoms. In the fourth I1- site, I1- is bonded in a distorted trigonal planar geometry to two equivalent Sr2+ and one Ca2+ atom. In the fifth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two Sr2+ and one Ca2+ atom. In the sixth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to three Sr2+ atoms.

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36 MATERIALS SCIENCECa-I-Srcrystal structureSr2CaI6

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2020-04-29. Materials Data on Sr2CaI6 by Materials Project. https://doi.org/10.17188/1300728

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