OsB4 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded in a 14-coordinate geometry to two equivalent B(2) and twelve equivalent B(1) atoms. In the second Os site, Os(2) is bonded to twelve equivalent B(1) atoms to form face-sharing OsB12 cuboctahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Os(1), two equivalent Os(2), two equivalent B(2), and three equivalent B(1) atoms. In the second B site, B(2) is bonded in a 8-coordinate geometry to one Os(1), one B(2), and six equivalent B(1) atoms.
OsB4 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded in a 14-coordinate geometry to two equivalent B(2) and twelve equivalent B(1) atoms. Both Os(1)-B(2) bond lengths are 2.36 Å. All Os(1)-B(1) bond lengths are 2.40 Å. In the second Os site, Os(2) is bonded to twelve equivalent B(1) atoms to form face-sharing OsB12 cuboctahedra. All Os(2)-B(1) bond lengths are 2.41 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Os(1), two equivalent Os(2), two equivalent B(2), and three equivalent B(1) atoms. Both B(1)-B(2) bond lengths are 1.93 Å. There is one shorter (1.77 Å) and two longer (1.79 Å) B(1)-B(1) bond lengths. In the second B site, B(2) is bonded in a 8-coordinate geometry to one Os(1), one B(2), and six equivalent B(1) atoms. The B(2)-B(2) bond length is 1.73 Å.