Ba2SiTe4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one Te(2), three equivalent Te(3), and four equivalent Te(1) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one Te(3), three equivalent Te(2), and four equivalent Te(1) atoms. Si(1) is bonded in a tetrahedral geometry to one Te(2), one Te(3), and two equivalent Te(1) atoms. There are three inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent Ba(1), two equivalent Ba(2), and one Si(1) atom to form a mixture of corner, edge, and face-sharing TeBa4Si square pyramids. In the second Te site, Te(2) is bonded in a 5-coordinate geometry to one Ba(1), three equivalent Ba(2), and one Si(1) atom. In the third Te site, Te(3) is bonded to one Ba(2), three equivalent Ba(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing TeBa4Si trigonal bipyramids.
Ba2SiTe4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one Te(2), three equivalent Te(3), and four equivalent Te(1) atoms. The Ba(1)-Te(2) bond length is 3.68 Å. There is one shorter (3.56 Å) and two longer (3.97 Å) Ba(1)-Te(3) bond lengths. There are two shorter (3.55 Å) and two longer (3.60 Å) Ba(1)-Te(1) bond lengths. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one Te(3), three equivalent Te(2), and four equivalent Te(1) atoms. The Ba(2)-Te(3) bond length is 3.49 Å. There is one shorter (3.59 Å) and two longer (4.02 Å) Ba(2)-Te(2) bond lengths. There are two shorter (3.57 Å) and two longer (3.64 Å) Ba(2)-Te(1) bond lengths. Si(1) is bonded in a tetrahedral geometry to one Te(2), one Te(3), and two equivalent Te(1) atoms. The Si(1)-Te(2) bond length is 2.52 Å. The Si(1)-Te(3) bond length is 2.52 Å. Both Si(1)-Te(1) bond lengths are 2.50 Å. There are three inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent Ba(1), two equivalent Ba(2), and one Si(1) atom to form a mixture of corner, edge, and face-sharing TeBa4Si square pyramids. In the second Te site, Te(2) is bonded in a 5-coordinate geometry to one Ba(1), three equivalent Ba(2), and one Si(1) atom. In the third Te site, Te(3) is bonded to one Ba(2), three equivalent Ba(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing TeBa4Si trigonal bipyramids.