Materials Data on U6Ta4Al43 by Materials Project

Abstract

U6Ta4Al43 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. U is bonded in a 8-coordinate geometry to one U, one Ta, and fifteen Al atoms. The U–U bond length is 3.23 Å. The U–Ta bond length is 3.56 Å. There are a spread of U–Al bond distances ranging from 3.07–3.51 Å. There are two inequivalent Ta sites. In the first Ta site, Ta is bonded to twelve Al atoms to form TaAl12 cuboctahedra that share edges with six equivalent AlTa2Al10 cuboctahedra. There are six shorter (2.70 Å) and six longer (2.91 Å) Ta–Al bond lengths. In the second Ta site, Ta is bonded in a distorted q6 geometry to two equivalent U and ten Al atoms. There are a spread of Ta–Al bond distances ranging from 2.66–2.76 Å. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 2-coordinate geometry to one U, two Ta, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.75–3.10 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent U, one Ta, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.75–3.04 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to four equivalent U and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.78–3.05 Å. In the fourth Al site, Al is bonded in a 12-coordinate geometry to two equivalent U, one Ta, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.72–3.05 Å. In the fifth Al site, Al is bonded in a 1-coordinate geometry to two equivalent U, one Ta, and seven Al atoms. There are two shorter (2.81 Å) and one longer (2.86 Å) Al–Al bond lengths. In the sixth Al site, Al is bonded to two equivalent Ta and ten Al atoms to form distorted AlTa2Al10 cuboctahedra that share corners with four equivalent AlU3Al9 cuboctahedra, edges with two equivalent TaAl12 cuboctahedra, and faces with two equivalent AlTa2Al10 cuboctahedra. Both Al–Al bond lengths are 2.82 Å. In the seventh Al site, Al is bonded to three equivalent U and nine Al atoms to form AlU3Al9 cuboctahedra that share corners with six AlTa2Al10 cuboctahedra and faces with two equivalent AlU3Al9 cuboctahedra.