SmPO4 is Zircon-like structured and crystallizes in the trigonal P3_221 space group. Sm(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted SmO8 hexagonal bipyramids that share corners with four equivalent P(1)O4 tetrahedra, edges with four equivalent Sm(1)O8 hexagonal bipyramids, and edges with two equivalent P(1)O4 tetrahedra. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with four equivalent Sm(1)O8 hexagonal bipyramids and edges with two equivalent Sm(1)O8 hexagonal bipyramids. There are two inequivalent O sites. In the first O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Sm(1) and one P(1) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Sm(1) and one P(1) atom.
SmPO4 is Zircon-like structured and crystallizes in the trigonal P3_221 space group. Sm(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted SmO8 hexagonal bipyramids that share corners with four equivalent P(1)O4 tetrahedra, edges with four equivalent Sm(1)O8 hexagonal bipyramids, and edges with two equivalent P(1)O4 tetrahedra. There are two shorter (2.37 Å) and two longer (2.51 Å) Sm(1)-O(1) bond lengths. There are two shorter (2.38 Å) and two longer (2.52 Å) Sm(1)-O(2) bond lengths. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with four equivalent Sm(1)O8 hexagonal bipyramids and edges with two equivalent Sm(1)O8 hexagonal bipyramids. Both P(1)-O(1) bond lengths are 1.53 Å. Both P(1)-O(2) bond lengths are 1.53 Å. There are two inequivalent O sites. In the first O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Sm(1) and one P(1) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Sm(1) and one P(1) atom.