Materials Data on Ca3Al2(SiO4)3 by Materials Project
Ca3Al2Si3O12 is Esseneite-like structured and crystallizes in the cubic Ia-3d space group. The structure is three-dimensional. Ca2+ is bonded in a distorted body-centered cubic geometry to eight equivalent O2- atoms. There are four shorter (2.34 Å) and four longer (2.52 Å) Ca–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 1.94 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 44°. All Si–O bond lengths are 1.66 Å. O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one Al3+, and one Si4+ atom.