Materials Data on U2MnAl3 by Materials Project
U2MnAl3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. U is bonded in a 6-coordinate geometry to three equivalent U, three equivalent Mn, and nine equivalent Al atoms. All U–U bond lengths are 2.99 Å. All U–Mn bond lengths are 2.94 Å. There are three shorter (3.02 Å) and six longer (3.21 Å) U–Al bond lengths. Mn is bonded to six equivalent U and six equivalent Al atoms to form MnU6Al6 cuboctahedra that share corners with six equivalent MnU6Al6 cuboctahedra, corners with twelve equivalent AlU6Mn2Al4 cuboctahedra, edges with six equivalent MnU6Al6 cuboctahedra, and faces with eighteen equivalent AlU6Mn2Al4 cuboctahedra. All Mn–Al bond lengths are 2.73 Å. Al is bonded to six equivalent U, two equivalent Mn, and four equivalent Al atoms to form AlU6Mn2Al4 cuboctahedra that share corners with four equivalent MnU6Al6 cuboctahedra, corners with fourteen equivalent AlU6Mn2Al4 cuboctahedra, edges with six equivalent AlU6Mn2Al4 cuboctahedra, faces with six equivalent MnU6Al6 cuboctahedra, and faces with twelve equivalent AlU6Mn2Al4 cuboctahedra. All Al–Al bond lengths are 2.53 Å.