KOs2O6 crystallizes in the trigonal R3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent O(3) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(3) atoms. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form corner-sharing OsO6 octahedra. The corner-sharing octahedral tilt angles range from 36-45°. In the second Os site, Os(2) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form corner-sharing OsO6 octahedra. The corner-sharing octahedral tilt angles range from 36-44°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Os(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(2), one Os(1), and one Os(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(1), one K(2), and two equivalent Os(1) atoms. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Os(1) and one Os(2) atom.
KOs2O6 crystallizes in the trigonal R3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent O(3) atoms. All K(1)-O(3) bond lengths are 2.80 Å. In the second K site, K(2) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(3) atoms. All K(2)-O(2) bond lengths are 2.78 Å. All K(2)-O(3) bond lengths are 3.04 Å. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form corner-sharing OsO6 octahedra. The corner-sharing octahedral tilt angles range from 36-45°. The Os(1)-O(2) bond length is 1.96 Å. The Os(1)-O(4) bond length is 1.88 Å. Both Os(1)-O(1) bond lengths are 1.89 Å. Both Os(1)-O(3) bond lengths are 1.94 Å. In the second Os site, Os(2) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form corner-sharing OsO6 octahedra. The corner-sharing octahedral tilt angles range from 36-44°. All Os(2)-O(2) bond lengths are 1.91 Å. All Os(2)-O(4) bond lengths are 1.91 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Os(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(2), one Os(1), and one Os(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(1), one K(2), and two equivalent Os(1) atoms. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Os(1) and one Os(2) atom.