DOI: 10.17188/1201820
title: Materials Data on Na8Ga2O7 by Materials Project

description: Na8Ga2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are eight inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.28–2.46 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with three NaO4 tetrahedra, corners with four GaO4 tetrahedra, and an edgeedge with one NaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–92°. There are a spread of Na–O bond distances ranging from 2.28–2.47 Å. In the third Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two NaO4 tetrahedra, corners with four GaO4 tetrahedra, an edgeedge with one NaO6 octahedra, and edges with three NaO4 tetrahedra. The corner-sharing octahedral tilt angles are 93°. There are a spread of Na–O bond distances ranging from 2.27–2.45 Å. In the fourth Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with eight NaO4 tetrahedra, edges with two NaO4 tetrahedra, and edges with four GaO4 tetrahedra. The corner-sharing octahedral tilt angles are 22°. There are a spread of Na–O bond distances ranging from 2.47–2.63 Å. In the fifth Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent NaO6 octahedra, corners with three GaO4 tetrahedra, corners with five NaO4 tetrahedra, an edgeedge with one NaO6 octahedra, an edgeedge with one NaO4 tetrahedra, and an edgeedge with one GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 15–55°. There are a spread of Na–O bond distances ranging from 2.28–2.49 Å. In the sixth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.31–2.72 Å. In the seventh Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with three equivalent NaO6 octahedra, corners with two GaO4 tetrahedra, corners with four NaO4 tetrahedra, an edgeedge with one GaO4 tetrahedra, and edges with two NaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–42°. There are a spread of Na–O bond distances ranging from 2.23–2.54 Å. In the eighth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.35–2.74 Å. There are two inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share a cornercorner with one GaO4 tetrahedra, corners with six NaO4 tetrahedra, edges with two equivalent NaO6 octahedra, and edges with two NaO4 tetrahedra. There are a spread of Ga–O bond distances ranging from 1.87–1.93 Å. In the second Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share a cornercorner with one GaO4 tetrahedra, corners with seven NaO4 tetrahedra, and edges with two equivalent NaO6 octahedra. There are a spread of Ga–O bond distances ranging from 1.87–1.94 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to five Na1+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing ONa5Ga octahedra. The corner-sharing octahedral tilt angles are 7°. In the second O2- site, O2- is bonded to five Na1+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing ONa5Ga octahedra. The corner-sharing octahedra tilt angles range from 7–66°. In the third O2- site, O2- is bonded in a 7-coordinate geometry to six Na1+ and one Ga3+ atom. In the fourth O2- site, O2- is bonded to five Na1+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing ONa5Ga octahedra. The corner-sharing octahedral tilt angles are 66°. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to four Na1+ and two Ga3+ atoms. In the sixth O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Ga3+ atom. In the seventh O2- site, O2- is bonded in a 7-coordinate geometry to six Na1+ and one Ga3+ atom.