Materials Data on Ca2BeSi2O7 by Materials Project
Ca2BeSi2O7 crystallizes in the tetragonal P-42_1m space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.38–2.83 Å. Be2+ is bonded to four equivalent O2- atoms to form BeO4 tetrahedra that share corners with four equivalent SiO4 tetrahedra. All Be–O bond lengths are 1.66 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with two equivalent BeO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ca2+, one Be2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded to three equivalent Ca2+ and one Si4+ atom to form a mixture of distorted edge and corner-sharing OCa3Si tetrahedra.