LiSm(FeO3)4 crystallizes in the tetragonal P4/mmm space group. Li(1) is bonded in a distorted square co-planar geometry to four equivalent O(3) atoms. Sm(1) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form SmO12 cuboctahedra that share corners with four equivalent Sm(1)O12 cuboctahedra and faces with eight equivalent Fe(1)O6 octahedra. Fe(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form FeO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra and faces with two equivalent Sm(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-9°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Sm(1) and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a distorted square co-planar geometry to two equivalent Sm(1) and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Li(1) and two equivalent Fe(1) atoms.
LiSm(FeO3)4 crystallizes in the tetragonal P4/mmm space group. Li(1) is bonded in a distorted square co-planar geometry to four equivalent O(3) atoms. All Li(1)-O(3) bond lengths are 2.68 Å. Sm(1) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form SmO12 cuboctahedra that share corners with four equivalent Sm(1)O12 cuboctahedra and faces with eight equivalent Fe(1)O6 octahedra. All Sm(1)-O(2) bond lengths are 2.68 Å. All Sm(1)-O(1) bond lengths are 2.59 Å. Fe(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form FeO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra and faces with two equivalent Sm(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-9°. The Fe(1)-O(2) bond length is 1.96 Å. The Fe(1)-O(3) bond length is 1.87 Å. All Fe(1)-O(1) bond lengths are 1.90 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Sm(1) and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a distorted square co-planar geometry to two equivalent Sm(1) and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Li(1) and two equivalent Fe(1) atoms.