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WTc crystallizes in the orthorhombic Cmmm space group. The structure is two-dimensional and consists of two WTc sheets oriented in the (0, 1, 0) direction. W3+ is bonded in a 4-coordinate geometry to four equivalent Tc3- atoms. All W–Tc bond lengths are 2.70 Å. Tc3- is bonded in a 4-coordinate geometry to four equivalent W3+ atoms.
WTc3 is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. W5+ is bonded to twelve equivalent Tc+1.67- atoms to form WTc12 cuboctahedra that share corners with six equivalent WTc12 cuboctahedra, corners with twelve equivalent TcTc8W4 cuboctahedra, edges with eighteen equivalent TcTc8W4 cuboctahedra, faces with eight equivalent WTc12 cuboctahedra, and faces with twelve equivalent TcTc8W4 cuboctahedra. There are six shorter (2.75 Å) and six longer (2.78 Å) W–Tc bond lengths. Tc+1.67- is bonded to four equivalent W5+ and eight equivalent Tc+1.67- atoms to form distorted TcTc8W4 cuboctahedra that share corners with four equivalent WTc12 cuboctahedra, corners with fourteen equivalent TcTc8W4 cuboctahedra, edges with six equivalent WTc12 cuboctahedra, edges with twelve equivalent TcTc8W4 cuboctahedra, faces with four equivalent WTc12 cuboctahedra, and faces with sixteen equivalent TcTc8W4 cuboctahedra. There are a spread of Tc–Tc bond distances ranging from 2.76–2.79 Å.