Sm2SiTeO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 4-coordinate geometry to four equivalent Te(1), one O(2), one O(3), and two equivalent O(1) atoms. In the second Sm site, Sm(2) is bonded in a 9-coordinate geometry to one Te(1), one O(1), two equivalent O(2), two equivalent O(3), and three equivalent O(4) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. Te(1) is bonded to one Sm(2) and four equivalent Sm(1) atoms to form distorted TeSm5 square pyramids that share corners with four equivalent Te(1)Sm5 square pyramids, corners with five equivalent O(1)Sm3Si trigonal pyramids, edges with four equivalent Te(1)Sm5 square pyramids, and edges with two equivalent O(1)Sm3Si trigonal pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Sm(2), two equivalent Sm(1), and one Si(1) atom to form distorted OSm3Si trigonal pyramids that share corners with five equivalent Te(1)Sm5 square pyramids, corners with two equivalent O(1)Sm3Si trigonal pyramids, and edges with two equivalent Te(1)Sm5 square pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sm(1), two equivalent Sm(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sm(1), two equivalent Sm(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to three equivalent Sm(2) and one Si(1) atom.
Sm2SiTeO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 4-coordinate geometry to four equivalent Te(1), one O(2), one O(3), and two equivalent O(1) atoms. There are a spread of Sm(1)-Te(1) bond distances ranging from 3.14-3.37 Å. The Sm(1)-O(2) bond length is 2.46 Å. The Sm(1)-O(3) bond length is 2.46 Å. There is one shorter (2.48 Å) and one longer (2.50 Å) Sm(1)-O(1) bond length. In the second Sm site, Sm(2) is bonded in a 9-coordinate geometry to one Te(1), one O(1), two equivalent O(2), two equivalent O(3), and three equivalent O(4) atoms. The Sm(2)-Te(1) bond length is 3.26 Å. The Sm(2)-O(1) bond length is 2.51 Å. There is one shorter (2.31 Å) and one longer (3.02 Å) Sm(2)-O(2) bond length. There is one shorter (2.38 Å) and one longer (2.65 Å) Sm(2)-O(3) bond length. There are a spread of Sm(2)-O(4) bond distances ranging from 2.40-2.70 Å. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Si(1)-O(1) bond length is 1.64 Å. The Si(1)-O(2) bond length is 1.61 Å. The Si(1)-O(3) bond length is 1.62 Å. The Si(1)-O(4) bond length is 1.63 Å. Te(1) is bonded to one Sm(2) and four equivalent Sm(1) atoms to form distorted TeSm5 square pyramids that share corners with four equivalent Te(1)Sm5 square pyramids, corners with five equivalent O(1)Sm3Si trigonal pyramids, edges with four equivalent Te(1)Sm5 square pyramids, and edges with two equivalent O(1)Sm3Si trigonal pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Sm(2), two equivalent Sm(1), and one Si(1) atom to form distorted OSm3Si trigonal pyramids that share corners with five equivalent Te(1)Sm5 square pyramids, corners with two equivalent O(1)Sm3Si trigonal pyramids, and edges with two equivalent Te(1)Sm5 square pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sm(1), two equivalent Sm(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sm(1), two equivalent Sm(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to three equivalent Sm(2) and one Si(1) atom.