DOI: 10.17188/1272969
title: Materials Data on La2AlNi9H2 by Materials Project

description: La2Ni9AlH2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent La sites. In the first La site, La is bonded in a distorted single-bond geometry to eight Ni and one H atom. There are a spread of La–Ni bond distances ranging from 2.87–3.20 Å. The La–H bond length is 2.38 Å. In the second La site, La is bonded in a 2-coordinate geometry to five Ni and two H atoms. There are a spread of La–Ni bond distances ranging from 2.89–3.17 Å. There are one shorter (2.35 Å) and one longer (2.36 Å) La–H bond lengths. There are nine inequivalent Ni sites. In the first Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent La, eight Ni, and one Al atom. There are a spread of Ni–Ni bond distances ranging from 2.44–2.98 Å. The Ni–Al bond length is 2.50 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent La, five Ni, and one Al atom. There are a spread of Ni–Ni bond distances ranging from 2.49–2.55 Å. The Ni–Al bond length is 2.44 Å. In the third Ni site, Ni is bonded in a single-bond geometry to five Ni and one H atom. There are two shorter (2.51 Å) and one longer (2.52 Å) Ni–Ni bond lengths. The Ni–H bond length is 1.58 Å. In the fourth Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent La, eight Ni, and one Al atom. There are a spread of Ni–Ni bond distances ranging from 2.48–2.54 Å. The Ni–Al bond length is 2.46 Å. In the fifth Ni site, Ni is bonded in a distorted single-bond geometry to three Ni, two equivalent Al, and one H atom. There are one shorter (2.51 Å) and one longer (2.52 Å) Ni–Al bond lengths. The Ni–H bond length is 1.62 Å. In the sixth Ni site, Ni is bonded in a single-bond geometry to five Ni and one H atom. There are one shorter (2.56 Å) and one longer (2.59 Å) Ni–Ni bond lengths. The Ni–H bond length is 1.57 Å. In the seventh Ni site, Ni is bonded to four La and eight Ni atoms to form NiLa4Ni8 cuboctahedra that share corners with four equivalent NiLa4Ni8 cuboctahedra, a cornercorner with one HLaNi3 tetrahedra, edges with two equivalent NiLa4Ni8 cuboctahedra, edges with two HLa2Ni2 tetrahedra, and faces with two equivalent HLa2Ni2 tetrahedra. The Ni–Ni bond length is 2.51 Å. In the eighth Ni site, Ni is bonded in a distorted single-bond geometry to one Ni, one Al, and one H atom. The Ni–Al bond length is 2.53 Å. The Ni–H bond length is 1.66 Å. In the ninth Ni site, Ni is bonded in a distorted single-bond geometry to three Ni, two equivalent Al, and one H atom. There are one shorter (2.52 Å) and one longer (2.53 Å) Ni–Al bond lengths. The Ni–H bond length is 1.62 Å. Al is bonded in a 12-coordinate geometry to eight Ni atoms. There are two inequivalent H sites. In the first H site, H is bonded to two La and two Ni atoms to form HLa2Ni2 tetrahedra that share a cornercorner with one HLaNi3 tetrahedra, an edgeedge with one NiLa4Ni8 cuboctahedra, and faces with two equivalent NiLa4Ni8 cuboctahedra. In the second H site, H is bonded to one La and three Ni atoms to form distorted HLaNi3 tetrahedra that share a cornercorner with one NiLa4Ni8 cuboctahedra, a cornercorner with one HLa2Ni2 tetrahedra, and an edgeedge with one NiLa4Ni8 cuboctahedra.