Ta4WC5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent C(1) and three equivalent C(3) atoms to form TaC6 octahedra that share corners with three equivalent Ta(2)C6 octahedra, corners with three equivalent W(1)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, edges with three equivalent W(1)C6 octahedra, and edges with six equivalent Ta(1)C6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Ta site, Ta(2) is bonded to three equivalent C(1) and three equivalent C(2) atoms to form a mixture of edge and corner-sharing TaC6 octahedra. The corner-sharing octahedra are not tilted. W(1) is bonded to six equivalent C(3) atoms to form WC6 octahedra that share corners with six equivalent Ta(1)C6 octahedra, edges with six equivalent Ta(1)C6 octahedra, and edges with six equivalent W(1)C6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are three inequivalent C sites. In the first C site, C(1) is bonded to three equivalent Ta(1) and three equivalent Ta(2) atoms to form CTa6 octahedra that share corners with three equivalent C(3)Ta3W3 octahedra, corners with three equivalent C(2)Ta6 octahedra, edges with three equivalent C(3)Ta3W3 octahedra, edges with three equivalent C(2)Ta6 octahedra, and edges with six equivalent C(1)Ta6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second C site, C(2) is bonded to six equivalent Ta(2) atoms to form a mixture of edge and corner-sharing CTa6 octahedra. The corner-sharing octahedra are not tilted. In the third C site, C(3) is bonded to three equivalent Ta(1) and three equivalent W(1) atoms to form CTa3W3 octahedra that share corners with three equivalent C(3)Ta3W3 octahedra, corners with three equivalent C(1)Ta6 octahedra, edges with three equivalent C(1)Ta6 octahedra, and edges with nine equivalent C(3)Ta3W3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°.
Ta4WC5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent C(1) and three equivalent C(3) atoms to form TaC6 octahedra that share corners with three equivalent Ta(2)C6 octahedra, corners with three equivalent W(1)C6 octahedra, edges with three equivalent Ta(2)C6 octahedra, edges with three equivalent W(1)C6 octahedra, and edges with six equivalent Ta(1)C6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. All Ta(1)-C(1) bond lengths are 2.23 Å. All Ta(1)-C(3) bond lengths are 2.25 Å. In the second Ta site, Ta(2) is bonded to three equivalent C(1) and three equivalent C(2) atoms to form a mixture of edge and corner-sharing TaC6 octahedra. The corner-sharing octahedra are not tilted. All Ta(2)-C(1) bond lengths are 2.24 Å. All Ta(2)-C(2) bond lengths are 2.24 Å. W(1) is bonded to six equivalent C(3) atoms to form WC6 octahedra that share corners with six equivalent Ta(1)C6 octahedra, edges with six equivalent Ta(1)C6 octahedra, and edges with six equivalent W(1)C6 octahedra. The corner-sharing octahedral tilt angles are 2°. All W(1)-C(3) bond lengths are 2.21 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded to three equivalent Ta(1) and three equivalent Ta(2) atoms to form CTa6 octahedra that share corners with three equivalent C(3)Ta3W3 octahedra, corners with three equivalent C(2)Ta6 octahedra, edges with three equivalent C(3)Ta3W3 octahedra, edges with three equivalent C(2)Ta6 octahedra, and edges with six equivalent C(1)Ta6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second C site, C(2) is bonded to six equivalent Ta(2) atoms to form a mixture of edge and corner-sharing CTa6 octahedra. The corner-sharing octahedra are not tilted. In the third C site, C(3) is bonded to three equivalent Ta(1) and three equivalent W(1) atoms to form CTa3W3 octahedra that share corners with three equivalent C(3)Ta3W3 octahedra, corners with three equivalent C(1)Ta6 octahedra, edges with three equivalent C(1)Ta6 octahedra, and edges with nine equivalent C(3)Ta3W3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°.