Tc2As3 crystallizes in the triclinic P-1 space group. There are four inequivalent Tc sites. In the first Tc site, Tc(1) is bonded in a 6-coordinate geometry to one As(1), one As(2), one As(3), one As(5), and two equivalent As(6) atoms. In the second Tc site, Tc(2) is bonded to one As(1), one As(2), one As(4), one As(6), and two equivalent As(5) atoms to form a mixture of distorted corner, edge, and face-sharing TcAs6 octahedra. The corner-sharing octahedral tilt angles range from 40-59°. In the third Tc site, Tc(3) is bonded to one As(1), one As(2), one As(3), one As(5), and two equivalent As(4) atoms to form a mixture of distorted corner, edge, and face-sharing TcAs6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. In the fourth Tc site, Tc(4) is bonded to one As(1), one As(2), one As(4), one As(6), and two equivalent As(3) atoms to form a mixture of distorted corner and edge-sharing TcAs6 octahedra. The corner-sharing octahedral tilt angles range from 40-59°. There are six inequivalent As sites. In the first As site, As(1) is bonded in a 5-coordinate geometry to one Tc(1), one Tc(2), one Tc(3), one Tc(4), and one As(2) atom. In the second As site, As(2) is bonded in a 5-coordinate geometry to one Tc(1), one Tc(2), one Tc(3), one Tc(4), and one As(1) atom. In the third As site, As(3) is bonded in a distorted rectangular see-saw-like geometry to one Tc(1), one Tc(3), and two equivalent Tc(4) atoms. In the fourth As site, As(4) is bonded in a 4-coordinate geometry to one Tc(2), one Tc(4), and two equivalent Tc(3) atoms. In the fifth As site, As(5) is bonded in a 5-coordinate geometry to one Tc(1), one Tc(3), two equivalent Tc(2), and one As(5) atom. In the sixth As site, As(6) is bonded in a 5-coordinate geometry to one Tc(2), one Tc(4), two equivalent Tc(1), and one As(6) atom.
Tc2As3 crystallizes in the triclinic P-1 space group. There are four inequivalent Tc sites. In the first Tc site, Tc(1) is bonded in a 6-coordinate geometry to one As(1), one As(2), one As(3), one As(5), and two equivalent As(6) atoms. The Tc(1)-As(1) bond length is 2.54 Å. The Tc(1)-As(2) bond length is 2.48 Å. The Tc(1)-As(3) bond length is 2.51 Å. The Tc(1)-As(5) bond length is 2.56 Å. There is one shorter (2.45 Å) and one longer (2.69 Å) Tc(1)-As(6) bond length. In the second Tc site, Tc(2) is bonded to one As(1), one As(2), one As(4), one As(6), and two equivalent As(5) atoms to form a mixture of distorted corner, edge, and face-sharing TcAs6 octahedra. The corner-sharing octahedral tilt angles range from 40-59°. The Tc(2)-As(1) bond length is 2.59 Å. The Tc(2)-As(2) bond length is 2.53 Å. The Tc(2)-As(4) bond length is 2.47 Å. The Tc(2)-As(6) bond length is 2.46 Å. There is one shorter (2.55 Å) and one longer (2.59 Å) Tc(2)-As(5) bond length. In the third Tc site, Tc(3) is bonded to one As(1), one As(2), one As(3), one As(5), and two equivalent As(4) atoms to form a mixture of distorted corner, edge, and face-sharing TcAs6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. The Tc(3)-As(1) bond length is 2.53 Å. The Tc(3)-As(2) bond length is 2.45 Å. The Tc(3)-As(3) bond length is 2.56 Å. The Tc(3)-As(5) bond length is 2.55 Å. There is one shorter (2.43 Å) and one longer (2.49 Å) Tc(3)-As(4) bond length. In the fourth Tc site, Tc(4) is bonded to one As(1), one As(2), one As(4), one As(6), and two equivalent As(3) atoms to form a mixture of distorted corner and edge-sharing TcAs6 octahedra. The corner-sharing octahedral tilt angles range from 40-59°. The Tc(4)-As(1) bond length is 2.56 Å. The Tc(4)-As(2) bond length is 2.48 Å. The Tc(4)-As(4) bond length is 2.42 Å. The Tc(4)-As(6) bond length is 2.53 Å. There is one shorter (2.44 Å) and one longer (2.55 Å) Tc(4)-As(3) bond length. There are six inequivalent As sites. In the first As site, As(1) is bonded in a 5-coordinate geometry to one Tc(1), one Tc(2), one Tc(3), one Tc(4), and one As(2) atom. The As(1)-As(2) bond length is 2.46 Å. In the second As site, As(2) is bonded in a 5-coordinate geometry to one Tc(1), one Tc(2), one Tc(3), one Tc(4), and one As(1) atom. In the third As site, As(3) is bonded in a distorted rectangular see-saw-like geometry to one Tc(1), one Tc(3), and two equivalent Tc(4) atoms. In the fourth As site, As(4) is bonded in a 4-coordinate geometry to one Tc(2), one Tc(4), and two equivalent Tc(3) atoms. In the fifth As site, As(5) is bonded in a 5-coordinate geometry to one Tc(1), one Tc(3), two equivalent Tc(2), and one As(5) atom. The As(5)-As(5) bond length is 2.79 Å. In the sixth As site, As(6) is bonded in a 5-coordinate geometry to one Tc(2), one Tc(4), two equivalent Tc(1), and one As(6) atom. The As(6)-As(6) bond length is 2.68 Å.