Materials Data on La6Mn9Al5 by Materials Project

Abstract

La6Mn9Al5 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent La sites. In the first La site, La is bonded in a 6-coordinate geometry to one Mn and five Al atoms. The La–Mn bond length is 3.22 Å. There are a spread of La–Al bond distances ranging from 3.33–3.39 Å. In the second La site, La is bonded in a 1-coordinate geometry to eight Mn and five Al atoms. There are four shorter (3.11 Å) and four longer (3.31 Å) La–Mn bond lengths. There are four shorter (3.32 Å) and one longer (3.37 Å) La–Al bond lengths. There are three inequivalent Mn sites. In the first Mn site, Mn is bonded to three La, six Mn, and three equivalent Al atoms to form distorted MnLa3Mn6Al3 cuboctahedra that share corners with seven equivalent MnLa3Mn6Al3 cuboctahedra, edges with four equivalent MnLa2Mn8Al2 cuboctahedra, and faces with fourteen MnLa3Mn6Al3 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.40–2.57 Å. There are one shorter (2.58 Å) and two longer (2.66 Å) Mn–Al bond lengths. In the second Mn site, Mn is bonded to eight Mn and four equivalent Al atoms to form MnMn8Al4 cuboctahedra that share corners with four equivalent MnLa2Mn8Al2 cuboctahedra and faces with sixteen MnLa3Mn6Al3 cuboctahedra. All Mn–Mn bond lengths are 2.47 Å. All Mn–Al bond lengths are 2.61 Å. In the third Mn site, Mn is bonded to two equivalent La, eight Mn, and two equivalent Al atoms to form MnLa2Mn8Al2 cuboctahedra that share corners with four MnMn8Al4 cuboctahedra, edges with four equivalent MnLa3Mn6Al3 cuboctahedra, and faces with fifteen MnLa3Mn6Al3 cuboctahedra. There are one shorter (2.57 Å) and two longer (2.61 Å) Mn–Mn bond lengths. Both Mn–Al bond lengths are 2.64 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a distorted q6 geometry to ten La atoms. In the second Al site, Al is bonded in a 12-coordinate geometry to five La, six Mn, and one Al atom. The Al–Al bond length is 2.84 Å.