SmB4 crystallizes in the tetragonal P4/mbm space group. Sm(1) is bonded in a 18-coordinate geometry to four equivalent B(2), six equivalent B(3), and eight equivalent B(1) atoms. There are three inequivalent B sites. In the first B site, B(2) is bonded in a 9-coordinate geometry to four equivalent Sm(1), one B(2), and four equivalent B(1) atoms. In the second B site, B(1) is bonded in a 9-coordinate geometry to four equivalent Sm(1), one B(3), two equivalent B(1), and two equivalent B(2) atoms. In the third B site, B(3) is bonded in a distorted trigonal planar geometry to six equivalent Sm(1), one B(3), and two equivalent B(1) atoms.
SmB4 crystallizes in the tetragonal P4/mbm space group. Sm(1) is bonded in a 18-coordinate geometry to four equivalent B(2), six equivalent B(3), and eight equivalent B(1) atoms. All Sm(1)-B(2) bond lengths are 2.76 Å. There are four shorter (2.90 Å) and two longer (3.10 Å) Sm(1)-B(3) bond lengths. There are four shorter (2.78 Å) and four longer (2.86 Å) Sm(1)-B(1) bond lengths. There are three inequivalent B sites. In the first B site, B(2) is bonded in a 9-coordinate geometry to four equivalent Sm(1), one B(2), and four equivalent B(1) atoms. The B(2)-B(2) bond length is 1.66 Å. All B(2)-B(1) bond lengths are 1.76 Å. In the second B site, B(1) is bonded in a 9-coordinate geometry to four equivalent Sm(1), one B(3), two equivalent B(1), and two equivalent B(2) atoms. The B(1)-B(3) bond length is 1.74 Å. Both B(1)-B(1) bond lengths are 1.82 Å. In the third B site, B(3) is bonded in a distorted trigonal planar geometry to six equivalent Sm(1), one B(3), and two equivalent B(1) atoms. The B(3)-B(3) bond length is 1.78 Å.