Materials Data on Al2Cr3(SiO4)3 by Materials Project
Cr3Al2(SiO4)3 is Esseneite-like structured and crystallizes in the cubic Ia-3d space group. The structure is three-dimensional. Cr2+ is bonded in a distorted body-centered cubic geometry to eight equivalent O2- atoms. There are four shorter (2.23 Å) and four longer (2.47 Å) Cr–O bond lengths. Al3+ is bonded to six equivalent O2- atoms to form AlO6 octahedra that share corners with six equivalent SiO4 tetrahedra. All Al–O bond lengths are 1.91 Å. Si4+ is bonded to four equivalent O2- atoms to form SiO4 tetrahedra that share corners with four equivalent AlO6 octahedra. The corner-sharing octahedral tilt angles are 46°. All Si–O bond lengths are 1.66 Å. O2- is bonded in a 4-coordinate geometry to two equivalent Cr2+, one Al3+, and one Si4+ atom.