Materials Data on Na4Al3FeO8 by Materials Project
Na4FeAl3O8 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with four NaO4 tetrahedra, and corners with six AlO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.36–2.42 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with four NaO4 tetrahedra, and corners with six AlO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.32–2.40 Å. In the third Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with four NaO4 tetrahedra, and corners with six AlO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.28–2.39 Å. In the fourth Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with four NaO4 tetrahedra, and corners with six AlO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.34–2.40 Å. Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with four AlO4 tetrahedra and corners with eight NaO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.89–1.91 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with two equivalent AlO4 tetrahedra, and corners with eight NaO4 tetrahedra. There is two shorter (1.78 Å) and two longer (1.79 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four AlO4 tetrahedra and corners with eight NaO4 tetrahedra. There is two shorter (1.78 Å) and two longer (1.79 Å) Al–O bond length. In the third Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with two equivalent AlO4 tetrahedra, and corners with eight NaO4 tetrahedra. There is three shorter (1.78 Å) and one longer (1.79 Å) Al–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to two Na1+, one Fe3+, and one Al3+ atom to form distorted corner-sharing ONa2AlFe trigonal pyramids. In the second O2- site, O2- is bonded to two Na1+, one Fe3+, and one Al3+ atom to form distorted corner-sharing ONa2AlFe trigonal pyramids. In the third O2- site, O2- is bonded to two Na1+ and two Al3+ atoms to form distorted corner-sharing ONa2Al2 trigonal pyramids. In the fourth O2- site, O2- is bonded to two Na1+ and two Al3+ atoms to form distorted corner-sharing ONa2Al2 trigonal pyramids. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one Al3+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+ and two Al3+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+ and two Al3+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Fe3+, and one Al3+ atom.