Materials Data on Mg6CdSiO8 by Materials Project
Mg6CdSiO8 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are three inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with four equivalent SiO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.17 Å) and four longer (2.22 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with four equivalent CdO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.19 Å) and four longer (2.22 Å) Mg–O bond lengths. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with two equivalent CdO6 octahedra, edges with two equivalent SiO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 2.15–2.22 Å. Cd is bonded to six O atoms to form CdO6 octahedra that share corners with two equivalent SiO6 octahedra, corners with four equivalent CdO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.22 Å) and two longer (2.33 Å) Cd–O bond lengths. Si is bonded to six O atoms to form SiO6 octahedra that share corners with two equivalent CdO6 octahedra, corners with four equivalent SiO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.03 Å) and four longer (2.22 Å) Si–O bond lengths. There are six inequivalent O sites. In the first O site, O is bonded to four equivalent Mg, one Cd, and one Si atom to form OMg4CdSi octahedra that share corners with six equivalent OMg4CdSi octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the second O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OMg4CdSi octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the third O site, O is bonded to four Mg and two equivalent Si atoms to form OMg4Si2 octahedra that share corners with six OMg4Si2 octahedra and edges with twelve OMg4CdSi octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth O site, O is bonded to four Mg and two equivalent Cd atoms to form OMg4Cd2 octahedra that share corners with six OMg4Si2 octahedra and edges with twelve OMg4CdSi octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth O site, O is bonded to four Mg and two equivalent Si atoms to form OMg4Si2 octahedra that share corners with six OMg4Si2 octahedra and edges with twelve OMg4CdSi octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–Mg bond lengths are 2.15 Å. In the sixth O site, O is bonded to four Mg and two equivalent Cd atoms to form OMg4Cd2 octahedra that share corners with six OMg4Si2 octahedra and edges with twelve OMg4CdSi octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–Mg bond lengths are 2.20 Å.