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Cr(H2O)6SiF6 crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of three chromium;hexahydrate molecules and three SiF6 clusters. In each SiF6 cluster, Si4+ is bonded in an octahedral geometry to six equivalent F1- atoms. All Si–F bond lengths are 1.72 Å. F1- is bonded in a single-bond geometry to one Si4+ atom.
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
CrSiH8(O2F3)2 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of two CrSiH8(O2F3)2 ribbons oriented in the (1, 0, 1) direction. Cr2+ is bonded to four O2- and two equivalent F1- atoms to form CrO4F2 octahedra that share corners with two equivalent SiF6 octahedra. The corner-sharing octahedral tilt angles are 18°. There are two shorter (2.06 Å) and two longer (2.09 Å) Cr–O bond lengths. Both Cr–F bond lengths are 2.45 Å. Si4+ is bonded to six F1- atoms to form SiF6 octahedra that share corners with two equivalent CrO4F2 octahedra. The corner-sharing octahedral tilt angles are 18°. There are a spread of Si–F bond distances ranging from 1.70–1.74 Å. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Cr2+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr2+ and two H1+ atoms. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to one Si4+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Si4+ atom. In the third F1- site, F1- is bonded in a distorted single-bond geometry to one Cr2+ and one Si4+ atom.