Ba3(SnP2)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one P(2), one P(4), two equivalent P(1), and two equivalent P(3) atoms to form a mixture of corner and edge-sharing BaP6 octahedra. The corner-sharing octahedral tilt angles range from 2-11°. In the second Ba site, Ba(2) is bonded to one P(1), one P(3), two equivalent P(2), and two equivalent P(4) atoms to form a mixture of corner and edge-sharing BaP6 octahedra. The corner-sharing octahedral tilt angles range from 8-12°. In the third Ba site, Ba(3) is bonded to one P(2), one P(4), two equivalent P(1), and two equivalent P(3) atoms to form a mixture of corner and edge-sharing BaP6 octahedra. The corner-sharing octahedral tilt angles range from 2-12°. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 3-coordinate geometry to one P(1), one P(2), and one P(3) atom. In the second Sn site, Sn(2) is bonded in a 3-coordinate geometry to one P(2) and two equivalent P(4) atoms. There are four inequivalent P sites. In the first P site, P(4) is bonded to one Ba(1), one Ba(3), two equivalent Ba(2), and two equivalent Sn(2) atoms to form distorted PBa4Sn2 octahedra that share corners with two equivalent P(2)Ba4Sn2 octahedra, corners with two equivalent P(3)Ba5Sn octahedra, corners with four equivalent P(1)Ba5Sn octahedra,  an edgeedge with one P(1)Ba5Sn octahedra, edges with two equivalent P(4)Ba4Sn2 octahedra, edges with two equivalent P(3)Ba5Sn octahedra, and edges with three equivalent P(2)Ba4Sn2 octahedra. The corner-sharing octahedral tilt angles range from 3-91°. In the second P site, P(1) is bonded to one Ba(2), two equivalent Ba(1), two equivalent Ba(3), and one Sn(1) atom to form PBa5Sn octahedra that share  a cornercorner with one P(2)Ba4Sn2 octahedra, corners with two equivalent P(3)Ba5Sn octahedra, corners with four equivalent P(4)Ba4Sn2 octahedra,  an edgeedge with one P(4)Ba4Sn2 octahedra, edges with two equivalent P(1)Ba5Sn octahedra, edges with three equivalent P(2)Ba4Sn2 octahedra, and edges with four equivalent P(3)Ba5Sn octahedra. The corner-sharing octahedral tilt angles range from 5-84°. In the third P site, P(2) is bonded to one Ba(1), one Ba(3), two equivalent Ba(2), one Sn(1), and one Sn(2) atom to form PBa4Sn2 octahedra that share  a cornercorner with one P(1)Ba5Sn octahedra, corners with two equivalent P(4)Ba4Sn2 octahedra, corners with three equivalent P(3)Ba5Sn octahedra,  an edgeedge with one P(2)Ba4Sn2 octahedra, edges with two equivalent P(3)Ba5Sn octahedra, edges with three equivalent P(4)Ba4Sn2 octahedra, and edges with three equivalent P(1)Ba5Sn octahedra. The corner-sharing octahedral tilt angles range from 3-78°. In the fourth P site, P(3) is bonded to one Ba(2), two equivalent Ba(1), two equivalent Ba(3), and one Sn(1) atom to form PBa5Sn octahedra that share corners with two equivalent P(4)Ba4Sn2 octahedra, corners with two equivalent P(1)Ba5Sn octahedra, corners with three equivalent P(2)Ba4Sn2 octahedra, edges with two equivalent P(2)Ba4Sn2 octahedra, edges with two equivalent P(4)Ba4Sn2 octahedra, edges with two equivalent P(3)Ba5Sn octahedra, and edges with four equivalent P(1)Ba5Sn octahedra. The corner-sharing octahedral tilt angles range from 5-91°.
Ba3(SnP2)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one P(2), one P(4), two equivalent P(1), and two equivalent P(3) atoms to form a mixture of corner and edge-sharing BaP6 octahedra. The corner-sharing octahedral tilt angles range from 2-11°. The Ba(1)-P(2) bond length is 3.26 Å. The Ba(1)-P(4) bond length is 3.38 Å. There is one shorter (3.27 Å) and one longer (3.37 Å) Ba(1)-P(1) bond length. There is one shorter (3.26 Å) and one longer (3.29 Å) Ba(1)-P(3) bond length. In the second Ba site, Ba(2) is bonded to one P(1), one P(3), two equivalent P(2), and two equivalent P(4) atoms to form a mixture of corner and edge-sharing BaP6 octahedra. The corner-sharing octahedral tilt angles range from 8-12°. The Ba(2)-P(1) bond length is 3.28 Å. The Ba(2)-P(3) bond length is 3.34 Å. There is one shorter (3.35 Å) and one longer (3.44 Å) Ba(2)-P(2) bond length. There is one shorter (3.34 Å) and one longer (3.43 Å) Ba(2)-P(4) bond length. In the third Ba site, Ba(3) is bonded to one P(2), one P(4), two equivalent P(1), and two equivalent P(3) atoms to form a mixture of corner and edge-sharing BaP6 octahedra. The corner-sharing octahedral tilt angles range from 2-12°. The Ba(3)-P(2) bond length is 3.33 Å. The Ba(3)-P(4) bond length is 3.41 Å. There is one shorter (3.23 Å) and one longer (3.28 Å) Ba(3)-P(1) bond length. There is one shorter (3.29 Å) and one longer (3.33 Å) Ba(3)-P(3) bond length. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 3-coordinate geometry to one P(1), one P(2), and one P(3) atom. The Sn(1)-P(1) bond length is 2.51 Å. The Sn(1)-P(2) bond length is 2.62 Å. The Sn(1)-P(3) bond length is 2.51 Å. In the second Sn site, Sn(2) is bonded in a 3-coordinate geometry to one P(2) and two equivalent P(4) atoms. The Sn(2)-P(2) bond length is 2.55 Å. There is one shorter (2.56 Å) and one longer (2.57 Å) Sn(2)-P(4) bond length. There are four inequivalent P sites. In the first P site, P(4) is bonded to one Ba(1), one Ba(3), two equivalent Ba(2), and two equivalent Sn(2) atoms to form distorted PBa4Sn2 octahedra that share corners with two equivalent P(2)Ba4Sn2 octahedra, corners with two equivalent P(3)Ba5Sn octahedra, corners with four equivalent P(1)Ba5Sn octahedra,  an edgeedge with one P(1)Ba5Sn octahedra, edges with two equivalent P(4)Ba4Sn2 octahedra, edges with two equivalent P(3)Ba5Sn octahedra, and edges with three equivalent P(2)Ba4Sn2 octahedra. The corner-sharing octahedral tilt angles range from 3-91°. In the second P site, P(1) is bonded to one Ba(2), two equivalent Ba(1), two equivalent Ba(3), and one Sn(1) atom to form PBa5Sn octahedra that share  a cornercorner with one P(2)Ba4Sn2 octahedra, corners with two equivalent P(3)Ba5Sn octahedra, corners with four equivalent P(4)Ba4Sn2 octahedra,  an edgeedge with one P(4)Ba4Sn2 octahedra, edges with two equivalent P(1)Ba5Sn octahedra, edges with three equivalent P(2)Ba4Sn2 octahedra, and edges with four equivalent P(3)Ba5Sn octahedra. The corner-sharing octahedral tilt angles range from 5-84°. In the third P site, P(2) is bonded to one Ba(1), one Ba(3), two equivalent Ba(2), one Sn(1), and one Sn(2) atom to form PBa4Sn2 octahedra that share  a cornercorner with one P(1)Ba5Sn octahedra, corners with two equivalent P(4)Ba4Sn2 octahedra, corners with three equivalent P(3)Ba5Sn octahedra,  an edgeedge with one P(2)Ba4Sn2 octahedra, edges with two equivalent P(3)Ba5Sn octahedra, edges with three equivalent P(4)Ba4Sn2 octahedra, and edges with three equivalent P(1)Ba5Sn octahedra. The corner-sharing octahedral tilt angles range from 3-78°. In the fourth P site, P(3) is bonded to one Ba(2), two equivalent Ba(1), two equivalent Ba(3), and one Sn(1) atom to form PBa5Sn octahedra that share corners with two equivalent P(4)Ba4Sn2 octahedra, corners with two equivalent P(1)Ba5Sn octahedra, corners with three equivalent P(2)Ba4Sn2 octahedra, edges with two equivalent P(2)Ba4Sn2 octahedra, edges with two equivalent P(4)Ba4Sn2 octahedra, edges with two equivalent P(3)Ba5Sn octahedra, and edges with four equivalent P(1)Ba5Sn octahedra. The corner-sharing octahedral tilt angles range from 5-91°.