ThMn3Al2 crystallizes in the orthorhombic Cmmm space group. Th(1) is bonded in a 18-coordinate geometry to four equivalent Mn(2), six equivalent Mn(1), and eight equivalent Al(1) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 10-coordinate geometry to three equivalent Th(1), one Mn(1), two equivalent Mn(2), and four equivalent Al(1) atoms. In the second Mn site, Mn(2) is bonded in a 8-coordinate geometry to four equivalent Th(1), four equivalent Mn(1), and four equivalent Al(1) atoms. Al(1) is bonded to four equivalent Th(1), two equivalent Mn(2), four equivalent Mn(1), and two equivalent Al(1) atoms to form a mixture of corner, face, and edge-sharing AlTh4Mn6Al2 cuboctahedra.
ThMn3Al2 crystallizes in the orthorhombic Cmmm space group. Th(1) is bonded in a 18-coordinate geometry to four equivalent Mn(2), six equivalent Mn(1), and eight equivalent Al(1) atoms. All Th(1)-Mn(2) bond lengths are 3.44 Å. There are two shorter (3.02 Å) and four longer (3.04 Å) Th(1)-Mn(1) bond lengths. All Th(1)-Al(1) bond lengths are 3.32 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 10-coordinate geometry to three equivalent Th(1), one Mn(1), two equivalent Mn(2), and four equivalent Al(1) atoms. The Mn(1)-Mn(1) bond length is 2.67 Å. Both Mn(1)-Mn(2) bond lengths are 2.49 Å. All Mn(1)-Al(1) bond lengths are 2.64 Å. In the second Mn site, Mn(2) is bonded in a 8-coordinate geometry to four equivalent Th(1), four equivalent Mn(1), and four equivalent Al(1) atoms. All Mn(2)-Al(1) bond lengths are 2.57 Å. Al(1) is bonded to four equivalent Th(1), two equivalent Mn(2), four equivalent Mn(1), and two equivalent Al(1) atoms to form a mixture of corner, face, and edge-sharing AlTh4Mn6Al2 cuboctahedra. Both Al(1)-Al(1) bond lengths are 2.73 Å.