LaOs4As12 crystallizes in the cubic Im-3 space group. La(1) is bonded to twelve equivalent As(1) atoms to form LaAs12 cuboctahedra that share faces with eight equivalent Os(1)As6 octahedra. Os(1) is bonded to six equivalent As(1) atoms to form OsAs6 octahedra that share corners with six equivalent Os(1)As6 octahedra and faces with two equivalent La(1)As12 cuboctahedra. The corner-sharing octahedral tilt angles are 59°. As(1) is bonded in a 5-coordinate geometry to one La(1), two equivalent Os(1), and two equivalent As(1) atoms.
LaOs4As12 crystallizes in the cubic Im-3 space group. La(1) is bonded to twelve equivalent As(1) atoms to form LaAs12 cuboctahedra that share faces with eight equivalent Os(1)As6 octahedra. All La(1)-As(1) bond lengths are 3.26 Å. Os(1) is bonded to six equivalent As(1) atoms to form OsAs6 octahedra that share corners with six equivalent Os(1)As6 octahedra and faces with two equivalent La(1)As12 cuboctahedra. The corner-sharing octahedral tilt angles are 59°. All Os(1)-As(1) bond lengths are 2.46 Å. As(1) is bonded in a 5-coordinate geometry to one La(1), two equivalent Os(1), and two equivalent As(1) atoms. There is one shorter (2.57 Å) and one longer (2.59 Å) As(1)-As(1) bond length.