Materials Data on Sr2CuSi2O7 by Materials Project
Sr2CuSi2O7 crystallizes in the tetragonal P-42_1m space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.58–2.88 Å. Cu2+ is bonded to four equivalent O2- atoms to form CuO4 tetrahedra that share corners with four equivalent SiO4 tetrahedra. All Cu–O bond lengths are 1.95 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 CuO4 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 Sr2+, one Cu2+, and one Si4+ atom. In the second O2- site, O2- is bonded to three equivalent Sr2+ and one Si4+ atom to form a mixture of distorted edge and corner-sharing OSr3Si tetrahedra. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+ and two equivalent Si4+ atoms.