Mg14NiAl crystallizes in the hexagonal P-6m2 space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4); four Mg(1,1); four Mg(3,3); and two equivalent Al(1) atoms to form distorted MgMg10Al2 cuboctahedra that share corners with four equivalent Ni(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Mg10Al2 cuboctahedra; corners with eight equivalent Mg(2)Mg10Ni2 cuboctahedra; edges with two equivalent Al(1)Mg12 cuboctahedra; edges with four Mg(1,1)Mg10Al2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Al(1)Mg12 cuboctahedra; and faces with four Mg(1,1)Mg10Al2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4); four equivalent Mg(2); four Mg(3,3); and two equivalent Ni(1) atoms to form distorted MgMg10Ni2 cuboctahedra that share corners with four equivalent Al(1)Mg12 cuboctahedra; corners with six equivalent Mg(2)Mg10Ni2 cuboctahedra; corners with eight Mg(1,1)Mg10Al2 cuboctahedra; edges with two equivalent Ni(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Ni2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(1)Mg10Al2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Ni(1)Mg12 cuboctahedra; and faces with four equivalent Mg(2)Mg10Ni2 cuboctahedra. In the third Mg site, Mg(1) is bonded to two equivalent Mg(4); four equivalent Mg(1); four Mg(3,3); and two equivalent Al(1) atoms to form distorted MgMg10Al2 cuboctahedra that share corners with four equivalent Ni(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Al2 cuboctahedra, corners with eight equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with two equivalent Al(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Al2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Al(1)Mg12 cuboctahedra, and faces with four equivalent Mg(1)Mg10Al2 cuboctahedra. In the fourth Mg site, Mg(3) is bonded in a 12-coordinate geometry to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); four Mg(3,3); one Ni(1); and one Al(1) atom. In the fifth Mg site, Mg(3) is bonded in a 12-coordinate geometry to two Mg(1,1); two equivalent Mg(2); two equivalent Mg(4); four equivalent Mg(3); one Ni(1); and one Al(1) atom. In the sixth Mg site, Mg(4) is bonded to three Mg(1,1); three equivalent Mg(2); and six Mg(3,3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra; edges with six Mg(1,1)Mg10Al2 cuboctahedra; edges with six equivalent Mg(2)Mg10Ni2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three Mg(1,1)Mg10Al2 cuboctahedra; faces with three equivalent Mg(2)Mg10Ni2 cuboctahedra; faces with three equivalent Ni(1)Mg12 cuboctahedra; and faces with three equivalent Al(1)Mg12 cuboctahedra. Ni(1) is bonded to six equivalent Mg(2) and six Mg(3,3) atoms to form NiMg12 cuboctahedra that share corners with six equivalent Ni(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Mg10Al2 cuboctahedra; edges with six equivalent Mg(2)Mg10Ni2 cuboctahedra; faces with two equivalent Al(1)Mg12 cuboctahedra; faces with six equivalent Mg(2)Mg10Ni2 cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra. Al(1) is bonded to six Mg(1,1) and six Mg(3,3) atoms to form AlMg12 cuboctahedra that share corners with six equivalent Al(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg10Ni2 cuboctahedra; edges with six Mg(1,1)Mg10Al2 cuboctahedra; faces with two equivalent Ni(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Al2 cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra.
Mg14NiAl crystallizes in the hexagonal P-6m2 space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4); four Mg(1,1); four Mg(3,3); and two equivalent Al(1) atoms to form distorted MgMg10Al2 cuboctahedra that share corners with four equivalent Ni(1)Mg12 cuboctahedra; corners with six equivalent Mg(1)Mg10Al2 cuboctahedra; corners with eight equivalent Mg(2)Mg10Ni2 cuboctahedra; edges with two equivalent Al(1)Mg12 cuboctahedra; edges with four Mg(1,1)Mg10Al2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Al(1)Mg12 cuboctahedra; and faces with four Mg(1,1)Mg10Al2 cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.06 Å. There are two shorter (3.11 Å) and two longer (3.12 Å) Mg(1)-Mg(1,1) bond lengths. All Mg(1)-Mg(3,3) bond lengths are 3.17 Å. Both Mg(1)-Al(1) bond lengths are 3.12 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4); four equivalent Mg(2); four Mg(3,3); and two equivalent Ni(1) atoms to form distorted MgMg10Ni2 cuboctahedra that share corners with four equivalent Al(1)Mg12 cuboctahedra; corners with six equivalent Mg(2)Mg10Ni2 cuboctahedra; corners with eight Mg(1,1)Mg10Al2 cuboctahedra; edges with two equivalent Ni(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Mg10Ni2 cuboctahedra; edges with four equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(1)Mg10Al2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Ni(1)Mg12 cuboctahedra; and faces with four equivalent Mg(2)Mg10Ni2 cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.07 Å. There are two shorter (3.07 Å) and two longer (3.16 Å) Mg(2)-Mg(2) bond lengths. All Mg(2)-Mg(3,3) bond lengths are 3.03 Å. Both Mg(2)-Ni(1) bond lengths are 3.12 Å. In the third Mg site, Mg(1) is bonded to two equivalent Mg(4); four equivalent Mg(1); four Mg(3,3); and two equivalent Al(1) atoms to form distorted MgMg10Al2 cuboctahedra that share corners with four equivalent Ni(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Al2 cuboctahedra, corners with eight equivalent Mg(2)Mg10Ni2 cuboctahedra, edges with two equivalent Al(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Al2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Al(1)Mg12 cuboctahedra, and faces with four equivalent Mg(1)Mg10Al2 cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.06 Å. All Mg(1)-Mg(3,3) bond lengths are 3.17 Å. Both Mg(1)-Al(1) bond lengths are 3.12 Å. In the fourth Mg site, Mg(3) is bonded in a 12-coordinate geometry to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); four Mg(3,3); one Ni(1); and one Al(1) atom. Both Mg(3)-Mg(4) bond lengths are 3.12 Å. There are two shorter (2.99 Å) and two longer (3.24 Å) Mg(3)-Mg(3,3) bond lengths. The Mg(3)-Ni(1) bond length is 2.96 Å. The Mg(3)-Al(1) bond length is 3.11 Å. In the fifth Mg site, Mg(3) is bonded in a 12-coordinate geometry to two Mg(1,1); two equivalent Mg(2); two equivalent Mg(4); four equivalent Mg(3); one Ni(1); and one Al(1) atom. Both Mg(3)-Mg(4) bond lengths are 3.12 Å. The Mg(3)-Ni(1) bond length is 2.96 Å. The Mg(3)-Al(1) bond length is 3.11 Å. In the sixth Mg site, Mg(4) is bonded to three Mg(1,1); three equivalent Mg(2); and six Mg(3,3) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra; edges with six Mg(1,1)Mg10Al2 cuboctahedra; edges with six equivalent Mg(2)Mg10Ni2 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three Mg(1,1)Mg10Al2 cuboctahedra; faces with three equivalent Mg(2)Mg10Ni2 cuboctahedra; faces with three equivalent Ni(1)Mg12 cuboctahedra; and faces with three equivalent Al(1)Mg12 cuboctahedra. Ni(1) is bonded to six equivalent Mg(2) and six Mg(3,3) atoms to form NiMg12 cuboctahedra that share corners with six equivalent Ni(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Mg10Al2 cuboctahedra; edges with six equivalent Mg(2)Mg10Ni2 cuboctahedra; faces with two equivalent Al(1)Mg12 cuboctahedra; faces with six equivalent Mg(2)Mg10Ni2 cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra. Al(1) is bonded to six Mg(1,1) and six Mg(3,3) atoms to form AlMg12 cuboctahedra that share corners with six equivalent Al(1)Mg12 cuboctahedra; corners with twelve equivalent Mg(2)Mg10Ni2 cuboctahedra; edges with six Mg(1,1)Mg10Al2 cuboctahedra; faces with two equivalent Ni(1)Mg12 cuboctahedra; faces with six Mg(1,1)Mg10Al2 cuboctahedra; and faces with six equivalent Mg(4)Mg12 cuboctahedra.