Sm5Si3O13 crystallizes in the hexagonal P6_3/m space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(3), and three equivalent O(4) atoms. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), and four equivalent O(4) atoms. Si(1) is bonded in a tetrahedral geometry to one O(2), one O(3), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent Sm(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Sm(2), two equivalent Sm(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sm(2), two equivalent Sm(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one Sm(1), two equivalent Sm(2), and one Si(1) atom.
Sm5Si3O13 crystallizes in the hexagonal P6_3/m space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(3), and three equivalent O(4) atoms. All Sm(1)-O(2) bond lengths are 2.42 Å. All Sm(1)-O(3) bond lengths are 2.51 Å. All Sm(1)-O(4) bond lengths are 2.85 Å. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), and four equivalent O(4) atoms. The Sm(2)-O(1) bond length is 2.26 Å. The Sm(2)-O(2) bond length is 2.71 Å. The Sm(2)-O(3) bond length is 2.46 Å. There are two shorter (2.38 Å) and two longer (2.50 Å) Sm(2)-O(4) bond lengths. Si(1) is bonded in a tetrahedral geometry to one O(2), one O(3), and two equivalent O(4) atoms. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.65 Å. Both Si(1)-O(4) bond lengths are 1.65 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to three equivalent Sm(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Sm(2), two equivalent Sm(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sm(2), two equivalent Sm(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one Sm(1), two equivalent Sm(2), and one Si(1) atom.