Ca2OsNiO6 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), three equivalent O(1), and three equivalent O(2) atoms. Os(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form OsO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-32°. Ni(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with six equivalent Os(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-32°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Os(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Os(1), and one Ni(1) atom. In the third O site, O(3) is bonded to two equivalent Ca(1), one Os(1), and one Ni(1) atom to form distorted corner-sharing OCa2NiOs tetrahedra.
Ca2OsNiO6 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), three equivalent O(1), and three equivalent O(2) atoms. There is one shorter (2.32 Å) and one longer (2.38 Å) Ca(1)-O(3) bond length. There are a spread of Ca(1)-O(1) bond distances ranging from 2.35-2.72 Å. There are a spread of Ca(1)-O(2) bond distances ranging from 2.34-2.69 Å. Os(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form OsO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-32°. Both Os(1)-O(1) bond lengths are 1.95 Å. Both Os(1)-O(2) bond lengths are 1.95 Å. Both Os(1)-O(3) bond lengths are 1.94 Å. Ni(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with six equivalent Os(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-32°. Both Ni(1)-O(1) bond lengths are 2.11 Å. Both Ni(1)-O(2) bond lengths are 2.09 Å. Both Ni(1)-O(3) bond lengths are 2.07 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Os(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Os(1), and one Ni(1) atom. In the third O site, O(3) is bonded to two equivalent Ca(1), one Os(1), and one Ni(1) atom to form distorted corner-sharing OCa2NiOs tetrahedra.