Materials Data on Sm2BeGa2O7 by Materials Project
BeSm2Ga2O7 is Esseneite-like structured and crystallizes in the tetragonal P-42_1m space group. The structure is three-dimensional. Be2+ is bonded to four equivalent O2- atoms to form BeO4 tetrahedra that share corners with four equivalent GaO4 tetrahedra. All Be–O bond lengths are 1.66 Å. Sm3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Sm–O bond distances ranging from 2.37–2.46 Å. Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share a cornercorner with one GaO4 tetrahedra and corners with two equivalent BeO4 tetrahedra. There are a spread of Ga–O bond distances ranging from 1.84–1.87 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Sm3+ and two equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OSm2Ga2 tetrahedra. In the second O2- site, O2- is bonded to three equivalent Sm3+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing OSm3Ga tetrahedra. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Be2+, one Sm3+, and one Ga3+ atom.