Materials Data on Al3Tc by Materials Project

Abstract

TcAl3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tc is bonded to twelve Al atoms to form TcAl12 cuboctahedra that share corners with four equivalent TcAl12 cuboctahedra, corners with eight equivalent AlAl8Tc4 cuboctahedra, edges with eight equivalent TcAl12 cuboctahedra, edges with sixteen equivalent AlAl8Tc4 cuboctahedra, faces with four equivalent TcAl12 cuboctahedra, and faces with fourteen AlAl8Tc4 cuboctahedra. There are four shorter (2.71 Å) and eight longer (2.78 Å) Tc–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Tc and eight Al atoms to form AlAl8Tc4 cuboctahedra that share corners with twelve equivalent AlAl8Tc4 cuboctahedra, edges with eight equivalent TcAl12 cuboctahedra, edges with sixteen AlAl8Tc4 cuboctahedra, faces with four equivalent TcAl12 cuboctahedra, and faces with fourteen AlAl8Tc4 cuboctahedra. There are four shorter (2.71 Å) and four longer (2.78 Å) Al–Al bond lengths. In the second Al site, Al is bonded to four equivalent Tc and eight equivalent Al atoms to form distorted AlAl8Tc4 cuboctahedra that share corners with four equivalent AlAl8Tc4 cuboctahedra, corners with eight equivalent TcAl12 cuboctahedra, edges with twenty-four AlAl8Tc4 cuboctahedra, faces with six equivalent TcAl12 cuboctahedra, and faces with twelve AlAl8Tc4 cuboctahedra.