Sn16P15 crystallizes in the triclinic P1 space group. There are sixteen inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 4-coordinate geometry to two equivalent Sn(9), one P(14), and one P(7) atom. In the second Sn site, Sn(2) is bonded in a 3-coordinate geometry to one P(7) and two equivalent P(9) atoms. In the third Sn site, Sn(3) is bonded in a distorted L-shaped geometry to one P(2) and one P(8) atom. In the fourth Sn site, Sn(4) is bonded in a distorted L-shaped geometry to one P(2) and two equivalent P(11) atoms. In the fifth Sn site, Sn(5) is bonded in a 1-coordinate geometry to two equivalent Sn(13) and two equivalent P(10) atoms. In the sixth Sn site, Sn(6) is bonded in a distorted L-shaped geometry to two equivalent Sn(14), one P(12), and one P(3) atom. In the seventh Sn site, Sn(7) is bonded in a distorted bent 150 degrees geometry to one P(13) and one P(5) atom. In the eighth Sn site, Sn(8) is bonded in a 4-coordinate geometry to two equivalent Sn(16), one P(13), and one P(14) atom. In the ninth Sn site, Sn(9) is bonded in a 4-coordinate geometry to two equivalent Sn(1), one P(14), and one P(7) atom. In the tenth Sn site, Sn(10) is bonded in a 3-coordinate geometry to one P(9) and two equivalent P(1) atoms. In the eleventh Sn site, Sn(11) is bonded in a distorted trigonal non-coplanar geometry to one P(6) and two equivalent P(8) atoms. In the twelfth Sn site, Sn(12) is bonded in a 1-coordinate geometry to one P(10), one P(11), and one P(6) atom. In the thirteenth Sn site, Sn(13) is bonded in a 5-coordinate geometry to two equivalent Sn(5), one P(3), and two equivalent P(10) atoms. In the fourteenth Sn site, Sn(14) is bonded in a 4-coordinate geometry to two equivalent Sn(6), one P(15), and one P(3) atom. In the fifteenth Sn site, Sn(15) is bonded in a distorted bent 150 degrees geometry to one P(15) and one P(4) atom. In the sixteenth Sn site, Sn(16) is bonded in a 2-coordinate geometry to two equivalent Sn(8), one P(14), and one P(4) atom. There are fifteen inequivalent P sites. In the first P site, P(1) is bonded in a trigonal planar geometry to two equivalent Sn(10) and one P(8) atom. In the second P site, P(2) is bonded to one Sn(3), one Sn(4), one P(11), and one P(6) atom to form distorted corner-sharing PSn2P2 tetrahedra. In the third P site, P(3) is bonded in a distorted T-shaped geometry to one Sn(13), one Sn(14), and one Sn(6) atom. In the fourth P site, P(4) is bonded in a distorted trigonal non-coplanar geometry to one Sn(15), one Sn(16), and one P(13) atom. In the fifth P site, P(5) is bonded in a distorted trigonal non-coplanar geometry to one Sn(7), one P(12), and one P(15) atom. In the sixth P site, P(6) is bonded in a distorted square co-planar geometry to one Sn(11), one Sn(12), one P(11), and one P(2) atom. In the seventh P site, P(7) is bonded in a distorted see-saw-like geometry to one Sn(1), one Sn(2), one Sn(9), and one P(9) atom. In the eighth P site, P(8) is bonded to one Sn(3), two equivalent Sn(11), and one P(1) atom to form distorted PSn3P tetrahedra that share  a cornercorner with one P(2)Sn2P2 tetrahedra and corners with two equivalent P(8)Sn3P tetrahedra. In the ninth P site, P(9) is bonded in a 4-coordinate geometry to one Sn(10), two equivalent Sn(2), and one P(7) atom. In the tenth P site, P(10) is bonded in a 5-coordinate geometry to one Sn(12), two equivalent Sn(13), and two equivalent Sn(5) atoms. In the eleventh P site, P(11) is bonded in a 5-coordinate geometry to one Sn(12), two equivalent Sn(4), one P(2), and one P(6) atom. In the twelfth P site, P(12) is bonded in a distorted trigonal non-coplanar geometry to one Sn(6), one P(15), and one P(5) atom. In the thirteenth P site, P(13) is bonded in a distorted T-shaped geometry to one Sn(7), one Sn(8), and one P(4) atom. In the fourteenth P site, P(14) is bonded in a 4-coordinate geometry to one Sn(1), one Sn(16), one Sn(8), and one Sn(9) atom. In the fifteenth P site, P(15) is bonded in a see-saw-like geometry to one Sn(14), one Sn(15), one P(12), and one P(5) atom.
Sn16P15 crystallizes in the triclinic P1 space group. There are sixteen inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 4-coordinate geometry to two equivalent Sn(9), one P(14), and one P(7) atom. There is one shorter (2.92 Å) and one longer (2.95 Å) Sn(1)-Sn(9) bond length. The Sn(1)-P(14) bond length is 2.68 Å. The Sn(1)-P(7) bond length is 2.65 Å. In the second Sn site, Sn(2) is bonded in a 3-coordinate geometry to one P(7) and two equivalent P(9) atoms. The Sn(2)-P(7) bond length is 2.80 Å. There is one shorter (2.82 Å) and one longer (2.95 Å) Sn(2)-P(9) bond length. In the third Sn site, Sn(3) is bonded in a distorted L-shaped geometry to one P(2) and one P(8) atom. The Sn(3)-P(2) bond length is 2.70 Å. The Sn(3)-P(8) bond length is 2.63 Å. In the fourth Sn site, Sn(4) is bonded in a distorted L-shaped geometry to one P(2) and two equivalent P(11) atoms. The Sn(4)-P(2) bond length is 2.70 Å. There is one shorter (2.77 Å) and one longer (3.14 Å) Sn(4)-P(11) bond length. In the fifth Sn site, Sn(5) is bonded in a 1-coordinate geometry to two equivalent Sn(13) and two equivalent P(10) atoms. There is one shorter (3.07 Å) and one longer (3.23 Å) Sn(5)-Sn(13) bond length. There is one shorter (2.75 Å) and one longer (3.14 Å) Sn(5)-P(10) bond length. In the sixth Sn site, Sn(6) is bonded in a distorted L-shaped geometry to two equivalent Sn(14), one P(12), and one P(3) atom. Both Sn(6)-Sn(14) bond lengths are 2.89 Å. The Sn(6)-P(12) bond length is 2.61 Å. The Sn(6)-P(3) bond length is 2.56 Å. In the seventh Sn site, Sn(7) is bonded in a distorted bent 150 degrees geometry to one P(13) and one P(5) atom. The Sn(7)-P(13) bond length is 2.76 Å. The Sn(7)-P(5) bond length is 2.69 Å. In the eighth Sn site, Sn(8) is bonded in a 4-coordinate geometry to two equivalent Sn(16), one P(13), and one P(14) atom. There is one shorter (2.88 Å) and one longer (2.92 Å) Sn(8)-Sn(16) bond length. The Sn(8)-P(13) bond length is 2.64 Å. The Sn(8)-P(14) bond length is 2.64 Å. In the ninth Sn site, Sn(9) is bonded in a 4-coordinate geometry to two equivalent Sn(1), one P(14), and one P(7) atom. The Sn(9)-P(14) bond length is 2.93 Å. The Sn(9)-P(7) bond length is 2.66 Å. In the tenth Sn site, Sn(10) is bonded in a 3-coordinate geometry to one P(9) and two equivalent P(1) atoms. The Sn(10)-P(9) bond length is 2.73 Å. There is one shorter (2.61 Å) and one longer (2.79 Å) Sn(10)-P(1) bond length. In the eleventh Sn site, Sn(11) is bonded in a distorted trigonal non-coplanar geometry to one P(6) and two equivalent P(8) atoms. The Sn(11)-P(6) bond length is 2.67 Å. There is one shorter (2.72 Å) and one longer (2.78 Å) Sn(11)-P(8) bond length. In the twelfth Sn site, Sn(12) is bonded in a 1-coordinate geometry to one P(10), one P(11), and one P(6) atom. The Sn(12)-P(10) bond length is 2.63 Å. The Sn(12)-P(11) bond length is 3.10 Å. The Sn(12)-P(6) bond length is 3.04 Å. In the thirteenth Sn site, Sn(13) is bonded in a 5-coordinate geometry to two equivalent Sn(5), one P(3), and two equivalent P(10) atoms. The Sn(13)-P(3) bond length is 2.62 Å. There is one shorter (2.65 Å) and one longer (3.07 Å) Sn(13)-P(10) bond length. In the fourteenth Sn site, Sn(14) is bonded in a 4-coordinate geometry to two equivalent Sn(6), one P(15), and one P(3) atom. The Sn(14)-P(15) bond length is 2.80 Å. The Sn(14)-P(3) bond length is 2.56 Å. In the fifteenth Sn site, Sn(15) is bonded in a distorted bent 150 degrees geometry to one P(15) and one P(4) atom. The Sn(15)-P(15) bond length is 2.82 Å. The Sn(15)-P(4) bond length is 2.68 Å. In the sixteenth Sn site, Sn(16) is bonded in a 2-coordinate geometry to two equivalent Sn(8), one P(14), and one P(4) atom. The Sn(16)-P(14) bond length is 2.61 Å. The Sn(16)-P(4) bond length is 2.61 Å. There are fifteen inequivalent P sites. In the first P site, P(1) is bonded in a trigonal planar geometry to two equivalent Sn(10) and one P(8) atom. The P(1)-P(8) bond length is 2.12 Å. In the second P site, P(2) is bonded to one Sn(3), one Sn(4), one P(11), and one P(6) atom to form distorted corner-sharing PSn2P2 tetrahedra. The P(2)-P(11) bond length is 2.39 Å. The P(2)-P(6) bond length is 2.24 Å. In the third P site, P(3) is bonded in a distorted T-shaped geometry to one Sn(13), one Sn(14), and one Sn(6) atom. In the fourth P site, P(4) is bonded in a distorted trigonal non-coplanar geometry to one Sn(15), one Sn(16), and one P(13) atom. The P(4)-P(13) bond length is 2.08 Å. In the fifth P site, P(5) is bonded in a distorted trigonal non-coplanar geometry to one Sn(7), one P(12), and one P(15) atom. The P(5)-P(12) bond length is 2.25 Å. The P(5)-P(15) bond length is 2.27 Å. In the sixth P site, P(6) is bonded in a distorted square co-planar geometry to one Sn(11), one Sn(12), one P(11), and one P(2) atom. The P(6)-P(11) bond length is 2.24 Å. In the seventh P site, P(7) is bonded in a distorted see-saw-like geometry to one Sn(1), one Sn(2), one Sn(9), and one P(9) atom. The P(7)-P(9) bond length is 2.17 Å. In the eighth P site, P(8) is bonded to one Sn(3), two equivalent Sn(11), and one P(1) atom to form distorted PSn3P tetrahedra that share  a cornercorner with one P(2)Sn2P2 tetrahedra and corners with two equivalent P(8)Sn3P tetrahedra. In the ninth P site, P(9) is bonded in a 4-coordinate geometry to one Sn(10), two equivalent Sn(2), and one P(7) atom. In the tenth P site, P(10) is bonded in a 5-coordinate geometry to one Sn(12), two equivalent Sn(13), and two equivalent Sn(5) atoms. In the eleventh P site, P(11) is bonded in a 5-coordinate geometry to one Sn(12), two equivalent Sn(4), one P(2), and one P(6) atom. In the twelfth P site, P(12) is bonded in a distorted trigonal non-coplanar geometry to one Sn(6), one P(15), and one P(5) atom. The P(12)-P(15) bond length is 2.32 Å. In the thirteenth P site, P(13) is bonded in a distorted T-shaped geometry to one Sn(7), one Sn(8), and one P(4) atom. In the fourteenth P site, P(14) is bonded in a 4-coordinate geometry to one Sn(1), one Sn(16), one Sn(8), and one Sn(9) atom. In the fifteenth P site, P(15) is bonded in a see-saw-like geometry to one Sn(14), one Sn(15), one P(12), and one P(5) atom.