Materials Data on MgNi4O9 by Materials Project
MgNi4O9 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.07–2.51 Å. In the second Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.06–2.46 Å. There are eight inequivalent Ni4+ sites. In the first Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.94–2.07 Å. In the second Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.95–2.03 Å. In the third Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing NiO5 square pyramids. There are a spread of Ni–O bond distances ranging from 1.95–2.03 Å. In the fourth Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.93–2.05 Å. In the fifth Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.85–2.08 Å. In the sixth Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.90–2.08 Å. In the seventh Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.88–2.09 Å. In the eighth Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.90–2.08 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ni4+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ni4+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.33 Å. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.36 Å. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.36 Å. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.32 Å. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. In the eleventh O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the fourteenth O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the fifteenth O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the sixteenth O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the eighteenth O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms.