ThB4 crystallizes in the tetragonal P4/mbm space group. Th(1) is bonded in a 18-coordinate geometry to four equivalent B(1), six equivalent B(2), and eight equivalent B(3) atoms. There are three inequivalent B sites. In the first B site, B(2) is bonded in a distorted trigonal planar geometry to six equivalent Th(1), one B(2), and two equivalent B(3) atoms. In the second B site, B(1) is bonded in a 9-coordinate geometry to four equivalent Th(1), one B(1), and four equivalent B(3) atoms. In the third B site, B(3) is bonded in a 9-coordinate geometry to four equivalent Th(1), one B(2), two equivalent B(1), and two equivalent B(3) atoms.
ThB4 crystallizes in the tetragonal P4/mbm space group. Th(1) is bonded in a 18-coordinate geometry to four equivalent B(1), six equivalent B(2), and eight equivalent B(3) atoms. All Th(1)-B(1) bond lengths are 2.78 Å. There are four shorter (2.95 Å) and two longer (3.10 Å) Th(1)-B(2) bond lengths. There are four shorter (2.82 Å) and four longer (2.88 Å) Th(1)-B(3) bond lengths. There are three inequivalent B sites. In the first B site, B(2) is bonded in a distorted trigonal planar geometry to six equivalent Th(1), one B(2), and two equivalent B(3) atoms. The B(2)-B(2) bond length is 1.84 Å. Both B(2)-B(3) bond lengths are 1.75 Å. In the second B site, B(1) is bonded in a 9-coordinate geometry to four equivalent Th(1), one B(1), and four equivalent B(3) atoms. The B(1)-B(1) bond length is 1.66 Å. All B(1)-B(3) bond lengths are 1.79 Å. In the third B site, B(3) is bonded in a 9-coordinate geometry to four equivalent Th(1), one B(2), two equivalent B(1), and two equivalent B(3) atoms. Both B(3)-B(3) bond lengths are 1.84 Å.