SmPt5Si3 crystallizes in the hexagonal P6_3/m space group. Sm(1) is bonded in a 12-coordinate geometry to two equivalent Pt(1), two equivalent Pt(4), two equivalent Pt(5), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. There are five inequivalent Pt sites. In the first Pt site, Pt(4) is bonded in a 6-coordinate geometry to two equivalent Sm(1), one Si(1), and three equivalent Si(2) atoms. In the second Pt site, Pt(5) is bonded in a 6-coordinate geometry to two equivalent Sm(1), one Si(2), and three equivalent Si(3) atoms. In the third Pt site, Pt(1) is bonded in a 6-coordinate geometry to two equivalent Sm(1), one Si(1), one Si(3), and two equivalent Si(2) atoms. In the fourth Pt site, Pt(2) is bonded in a 5-coordinate geometry to one Si(2) and four equivalent Si(1) atoms. In the fifth Pt site, Pt(3) is bonded in a trigonal non-coplanar geometry to three equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to two equivalent Sm(1), one Pt(1), one Pt(4), and four equivalent Pt(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sm(1), one Pt(2), one Pt(5), two equivalent Pt(1), and three equivalent Pt(4) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Sm(1), one Pt(1), three equivalent Pt(3), and three equivalent Pt(5) atoms.
SmPt5Si3 crystallizes in the hexagonal P6_3/m space group. Sm(1) is bonded in a 12-coordinate geometry to two equivalent Pt(1), two equivalent Pt(4), two equivalent Pt(5), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. Both Sm(1)-Pt(1) bond lengths are 3.12 Å. Both Sm(1)-Pt(4) bond lengths are 3.19 Å. Both Sm(1)-Pt(5) bond lengths are 3.10 Å. Both Sm(1)-Si(1) bond lengths are 3.13 Å. Both Sm(1)-Si(2) bond lengths are 3.13 Å. Both Sm(1)-Si(3) bond lengths are 3.17 Å. There are five inequivalent Pt sites. In the first Pt site, Pt(4) is bonded in a 6-coordinate geometry to two equivalent Sm(1), one Si(1), and three equivalent Si(2) atoms. The Pt(4)-Si(1) bond length is 2.39 Å. There is one shorter (2.42 Å) and two longer (2.58 Å) Pt(4)-Si(2) bond lengths. In the second Pt site, Pt(5) is bonded in a 6-coordinate geometry to two equivalent Sm(1), one Si(2), and three equivalent Si(3) atoms. The Pt(5)-Si(2) bond length is 2.39 Å. There is one shorter (2.43 Å) and two longer (2.65 Å) Pt(5)-Si(3) bond lengths. In the third Pt site, Pt(1) is bonded in a 6-coordinate geometry to two equivalent Sm(1), one Si(1), one Si(3), and two equivalent Si(2) atoms. The Pt(1)-Si(1) bond length is 2.44 Å. The Pt(1)-Si(3) bond length is 2.44 Å. Both Pt(1)-Si(2) bond lengths are 2.65 Å. In the fourth Pt site, Pt(2) is bonded in a 5-coordinate geometry to one Si(2) and four equivalent Si(1) atoms. The Pt(2)-Si(2) bond length is 2.46 Å. There are two shorter (2.53 Å) and two longer (2.73 Å) Pt(2)-Si(1) bond lengths. In the fifth Pt site, Pt(3) is bonded in a trigonal non-coplanar geometry to three equivalent Si(3) atoms. There is one shorter (2.41 Å) and two longer (2.50 Å) Pt(3)-Si(3) bond lengths. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to two equivalent Sm(1), one Pt(1), one Pt(4), and four equivalent Pt(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sm(1), one Pt(2), one Pt(5), two equivalent Pt(1), and three equivalent Pt(4) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Sm(1), one Pt(1), three equivalent Pt(3), and three equivalent Pt(5) atoms.