Materials Data on Tc3As by Materials Project

Abstract

Tc3As is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Tc+1.67- sites. In the first Tc+1.67- site, Tc+1.67- is bonded to eight Tc+1.67- and four equivalent As5+ atoms to form TcTc8As4 cuboctahedra that share corners with twelve equivalent TcTc8As4 cuboctahedra, edges with eight equivalent TcTc8As4 cuboctahedra, edges with eight equivalent AsTc12 cuboctahedra, faces with four equivalent AsTc12 cuboctahedra, and faces with ten equivalent TcTc8As4 cuboctahedra. There are four shorter (2.66 Å) and four longer (2.80 Å) Tc–Tc bond lengths. All Tc–As bond lengths are 2.80 Å. In the second Tc+1.67- site, Tc+1.67- is bonded in a distorted square co-planar geometry to eight equivalent Tc+1.67- and four equivalent As5+ atoms. All Tc–As bond lengths are 2.66 Å. As5+ is bonded to twelve Tc+1.67- atoms to form AsTc12 cuboctahedra that share corners with four equivalent AsTc12 cuboctahedra, edges with eight equivalent AsTc12 cuboctahedra, edges with sixteen equivalent TcTc8As4 cuboctahedra, faces with four equivalent AsTc12 cuboctahedra, and faces with eight equivalent TcTc8As4 cuboctahedra.