Materials Data on NaCaGaSi2O7 by Materials Project

Abstract

NaCaGaSi2O7 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. Na1+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.49 Å. Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.23–2.73 Å. Ga3+ is bonded in an L-shaped geometry to two O2- atoms. There are one shorter (1.95 Å) and one longer (2.35 Å) Ga–O bond lengths. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.69 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+, one Ca2+, one Ga3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ca2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Na1+, one Ca2+, and one O2- atom. The O–O bond length is 1.49 Å. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one Si4+, and one O2- atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ga3+, and one Si4+ atom.