La3Os2O10 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a body-centered cubic geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. In the second La site, La(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Os(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form edge-sharing OsO6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent La(2) and one Os(1) atom. In the second O site, O(2) is bonded to one La(1), two equivalent La(2), and one Os(1) atom to form a mixture of edge and corner-sharing OLa3Os tetrahedra. In the third O site, O(3) is bonded to one La(1), two equivalent La(2), and one Os(1) atom to form a mixture of distorted edge and corner-sharing OLa3Os trigonal pyramids. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one La(1) and two equivalent Os(1) atoms.
La3Os2O10 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a body-centered cubic geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. Both La(1)-O(2) bond lengths are 2.40 Å. Both La(1)-O(4) bond lengths are 2.60 Å. All La(1)-O(3) bond lengths are 2.52 Å. In the second La site, La(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Both La(2)-O(1) bond lengths are 2.42 Å. Both La(2)-O(2) bond lengths are 2.47 Å. There are two shorter (2.67 Å) and two longer (2.69 Å) La(2)-O(3) bond lengths. Os(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form edge-sharing OsO6 octahedra. The Os(1)-O(1) bond length is 1.96 Å. The Os(1)-O(2) bond length is 1.94 Å. Both Os(1)-O(3) bond lengths are 1.91 Å. Both Os(1)-O(4) bond lengths are 2.00 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent La(2) and one Os(1) atom. In the second O site, O(2) is bonded to one La(1), two equivalent La(2), and one Os(1) atom to form a mixture of edge and corner-sharing OLa3Os tetrahedra. In the third O site, O(3) is bonded to one La(1), two equivalent La(2), and one Os(1) atom to form a mixture of distorted edge and corner-sharing OLa3Os trigonal pyramids. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one La(1) and two equivalent Os(1) atoms.