Nb12Tl(AsTe3)4 crystallizes in the monoclinic Cm space group. There are nine inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent As(3), one Te(2), one Te(6), and two equivalent Te(7) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the second Nb site, Nb(2) is bonded to two equivalent As(3), one Te(1), one Te(5), and two equivalent Te(7) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the third Nb site, Nb(3) is bonded to two equivalent As(3), one Te(2), one Te(4), and two equivalent Te(8) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. In the fourth Nb site, Nb(4) is bonded to two equivalent As(3), one Te(1), one Te(3), and two equivalent Te(8) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the fifth Nb site, Nb(5) is bonded to two equivalent As(3), one Te(4), one Te(6), and two equivalent Te(9) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the sixth Nb site, Nb(6) is bonded to two equivalent As(3), one Te(3), one Te(5), and two equivalent Te(9) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the seventh Nb site, Nb(7) is bonded to one As(1), one As(2), one Te(1), one Te(2), one Te(7), and one Te(9) atom to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the eighth Nb site, Nb(8) is bonded to one As(1), one As(2), one Te(3), one Te(4), one Te(7), and one Te(8) atom to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the ninth Nb site, Nb(9) is bonded to one As(1), one As(2), one Te(5), one Te(6), one Te(8), and one Te(9) atom to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. Tl(1) is bonded in a trigonal planar geometry to one Te(2), one Te(4), and one Te(5) atom. There are three inequivalent As sites. In the first As site, As(1) is bonded to two equivalent Nb(7), two equivalent Nb(8), and two equivalent Nb(9) atoms to form distorted face-sharing AsNb6 pentagonal pyramids. In the second As site, As(2) is bonded to two equivalent Nb(7), two equivalent Nb(8), and two equivalent Nb(9) atoms to form distorted face-sharing AsNb6 pentagonal pyramids. In the third As site, As(3) is bonded to one Nb(1), one Nb(2), one Nb(3), one Nb(4), one Nb(5), and one Nb(6) atom to form distorted face-sharing AsNb6 pentagonal pyramids. There are nine inequivalent Te sites. In the first Te site, Te(1) is bonded in a 4-coordinate geometry to one Nb(2), one Nb(4), and two equivalent Nb(7) atoms. In the second Te site, Te(2) is bonded in a 5-coordinate geometry to one Nb(1), one Nb(3), two equivalent Nb(7), and one Tl(1) atom. In the third Te site, Te(3) is bonded in a 4-coordinate geometry to one Nb(4), one Nb(6), and two equivalent Nb(8) atoms. In the fourth Te site, Te(4) is bonded in a 5-coordinate geometry to one Nb(3), one Nb(5), two equivalent Nb(8), and one Tl(1) atom. In the fifth Te site, Te(5) is bonded in a 5-coordinate geometry to one Nb(2), one Nb(6), two equivalent Nb(9), and one Tl(1) atom. In the sixth Te site, Te(6) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(5), and two equivalent Nb(9) atoms. In the seventh Te site, Te(7) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(2), one Nb(7), and one Nb(8) atom. In the eighth Te site, Te(8) is bonded in a 4-coordinate geometry to one Nb(3), one Nb(4), one Nb(8), and one Nb(9) atom. In the ninth Te site, Te(9) is bonded in a 4-coordinate geometry to one Nb(5), one Nb(6), one Nb(7), and one Nb(9) atom.
Nb12Tl(AsTe3)4 crystallizes in the monoclinic Cm space group. There are nine inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent As(3), one Te(2), one Te(6), and two equivalent Te(7) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. Both Nb(1)-As(3) bond lengths are 2.68 Å. The Nb(1)-Te(2) bond length is 2.75 Å. The Nb(1)-Te(6) bond length is 2.95 Å. Both Nb(1)-Te(7) bond lengths are 2.82 Å. In the second Nb site, Nb(2) is bonded to two equivalent As(3), one Te(1), one Te(5), and two equivalent Te(7) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. Both Nb(2)-As(3) bond lengths are 2.68 Å. The Nb(2)-Te(1) bond length is 2.77 Å. The Nb(2)-Te(5) bond length is 2.97 Å. Both Nb(2)-Te(7) bond lengths are 2.83 Å. In the third Nb site, Nb(3) is bonded to two equivalent As(3), one Te(2), one Te(4), and two equivalent Te(8) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. Both Nb(3)-As(3) bond lengths are 2.68 Å. The Nb(3)-Te(2) bond length is 2.95 Å. The Nb(3)-Te(4) bond length is 2.75 Å. Both Nb(3)-Te(8) bond lengths are 2.83 Å. In the fourth Nb site, Nb(4) is bonded to two equivalent As(3), one Te(1), one Te(3), and two equivalent Te(8) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. Both Nb(4)-As(3) bond lengths are 2.68 Å. The Nb(4)-Te(1) bond length is 2.98 Å. The Nb(4)-Te(3) bond length is 2.77 Å. Both Nb(4)-Te(8) bond lengths are 2.83 Å. In the fifth Nb site, Nb(5) is bonded to two equivalent As(3), one Te(4), one Te(6), and two equivalent Te(9) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. Both Nb(5)-As(3) bond lengths are 2.68 Å. The Nb(5)-Te(4) bond length is 2.97 Å. The Nb(5)-Te(6) bond length is 2.77 Å. Both Nb(5)-Te(9) bond lengths are 2.83 Å. In the sixth Nb site, Nb(6) is bonded to two equivalent As(3), one Te(3), one Te(5), and two equivalent Te(9) atoms to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. Both Nb(6)-As(3) bond lengths are 2.68 Å. The Nb(6)-Te(3) bond length is 2.95 Å. The Nb(6)-Te(5) bond length is 2.75 Å. Both Nb(6)-Te(9) bond lengths are 2.82 Å. In the seventh Nb site, Nb(7) is bonded to one As(1), one As(2), one Te(1), one Te(2), one Te(7), and one Te(9) atom to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. The Nb(7)-As(1) bond length is 2.68 Å. The Nb(7)-As(2) bond length is 2.68 Å. The Nb(7)-Te(1) bond length is 2.83 Å. The Nb(7)-Te(2) bond length is 2.82 Å. The Nb(7)-Te(7) bond length is 2.77 Å. The Nb(7)-Te(9) bond length is 2.98 Å. In the eighth Nb site, Nb(8) is bonded to one As(1), one As(2), one Te(3), one Te(4), one Te(7), and one Te(8) atom to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. The Nb(8)-As(1) bond length is 2.68 Å. The Nb(8)-As(2) bond length is 2.68 Å. The Nb(8)-Te(3) bond length is 2.83 Å. The Nb(8)-Te(4) bond length is 2.82 Å. The Nb(8)-Te(7) bond length is 2.98 Å. The Nb(8)-Te(8) bond length is 2.77 Å. In the ninth Nb site, Nb(9) is bonded to one As(1), one As(2), one Te(5), one Te(6), one Te(8), and one Te(9) atom to form a mixture of distorted corner, face, and edge-sharing NbTe4As2 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. The Nb(9)-As(1) bond length is 2.68 Å. The Nb(9)-As(2) bond length is 2.68 Å. The Nb(9)-Te(5) bond length is 2.82 Å. The Nb(9)-Te(6) bond length is 2.83 Å. The Nb(9)-Te(8) bond length is 2.98 Å. The Nb(9)-Te(9) bond length is 2.77 Å. Tl(1) is bonded in a trigonal planar geometry to one Te(2), one Te(4), and one Te(5) atom. The Tl(1)-Te(2) bond length is 3.29 Å. The Tl(1)-Te(4) bond length is 3.28 Å. The Tl(1)-Te(5) bond length is 3.28 Å. There are three inequivalent As sites. In the first As site, As(1) is bonded to two equivalent Nb(7), two equivalent Nb(8), and two equivalent Nb(9) atoms to form distorted face-sharing AsNb6 pentagonal pyramids. In the second As site, As(2) is bonded to two equivalent Nb(7), two equivalent Nb(8), and two equivalent Nb(9) atoms to form distorted face-sharing AsNb6 pentagonal pyramids. In the third As site, As(3) is bonded to one Nb(1), one Nb(2), one Nb(3), one Nb(4), one Nb(5), and one Nb(6) atom to form distorted face-sharing AsNb6 pentagonal pyramids. There are nine inequivalent Te sites. In the first Te site, Te(1) is bonded in a 4-coordinate geometry to one Nb(2), one Nb(4), and two equivalent Nb(7) atoms. In the second Te site, Te(2) is bonded in a 5-coordinate geometry to one Nb(1), one Nb(3), two equivalent Nb(7), and one Tl(1) atom. In the third Te site, Te(3) is bonded in a 4-coordinate geometry to one Nb(4), one Nb(6), and two equivalent Nb(8) atoms. In the fourth Te site, Te(4) is bonded in a 5-coordinate geometry to one Nb(3), one Nb(5), two equivalent Nb(8), and one Tl(1) atom. In the fifth Te site, Te(5) is bonded in a 5-coordinate geometry to one Nb(2), one Nb(6), two equivalent Nb(9), and one Tl(1) atom. In the sixth Te site, Te(6) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(5), and two equivalent Nb(9) atoms. In the seventh Te site, Te(7) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(2), one Nb(7), and one Nb(8) atom. In the eighth Te site, Te(8) is bonded in a 4-coordinate geometry to one Nb(3), one Nb(4), one Nb(8), and one Nb(9) atom. In the ninth Te site, Te(9) is bonded in a 4-coordinate geometry to one Nb(5), one Nb(6), one Nb(7), and one Nb(9) atom.