NiCu2Al2 crystallizes in the tetragonal P4mm space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 10-coordinate geometry to four equivalent Cu(3), four equivalent Cu(4), one Al(1), and one Al(4) atom. In the second Ni site, Ni(2) is bonded in a body-centered cubic geometry to four equivalent Al(1) and four equivalent Al(2) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a body-centered cubic geometry to four equivalent Al(2) and four equivalent Al(3) atoms. In the second Cu site, Cu(2) is bonded in a body-centered cubic geometry to four equivalent Al(3) and four equivalent Al(4) atoms. In the third Cu site, Cu(3) is bonded in a 8-coordinate geometry to four equivalent Ni(1) and four equivalent Al(4) atoms. In the fourth Cu site, Cu(4) is bonded in a 8-coordinate geometry to four equivalent Ni(1) and four equivalent Al(1) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted body-centered cubic geometry to one Ni(1), four equivalent Ni(2), and four equivalent Cu(4) atoms. In the second Al site, Al(2) is bonded in a body-centered cubic geometry to four equivalent Ni(2) and four equivalent Cu(1) atoms. In the third Al site, Al(3) is bonded in a body-centered cubic geometry to four equivalent Cu(1) and four equivalent Cu(2) atoms. In the fourth Al site, Al(4) is bonded in a 9-coordinate geometry to one Ni(1), four equivalent Cu(2), and four equivalent Cu(3) atoms.
NiCu2Al2 crystallizes in the tetragonal P4mm space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 10-coordinate geometry to four equivalent Cu(3), four equivalent Cu(4), one Al(1), and one Al(4) atom. All Ni(1)-Cu(3) bond lengths are 2.49 Å. All Ni(1)-Cu(4) bond lengths are 2.50 Å. The Ni(1)-Al(1) bond length is 2.80 Å. The Ni(1)-Al(4) bond length is 2.73 Å. In the second Ni site, Ni(2) is bonded in a body-centered cubic geometry to four equivalent Al(1) and four equivalent Al(2) atoms. All Ni(2)-Al(1) bond lengths are 2.54 Å. All Ni(2)-Al(2) bond lengths are 2.49 Å. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a body-centered cubic geometry to four equivalent Al(2) and four equivalent Al(3) atoms. All Cu(1)-Al(2) bond lengths are 2.58 Å. All Cu(1)-Al(3) bond lengths are 2.56 Å. In the second Cu site, Cu(2) is bonded in a body-centered cubic geometry to four equivalent Al(3) and four equivalent Al(4) atoms. All Cu(2)-Al(3) bond lengths are 2.56 Å. All Cu(2)-Al(4) bond lengths are 2.59 Å. In the third Cu site, Cu(3) is bonded in a 8-coordinate geometry to four equivalent Ni(1) and four equivalent Al(4) atoms. All Cu(3)-Al(4) bond lengths are 2.50 Å. In the fourth Cu site, Cu(4) is bonded in a 8-coordinate geometry to four equivalent Ni(1) and four equivalent Al(1) atoms. All Cu(4)-Al(1) bond lengths are 2.53 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted body-centered cubic geometry to one Ni(1), four equivalent Ni(2), and four equivalent Cu(4) atoms. In the second Al site, Al(2) is bonded in a body-centered cubic geometry to four equivalent Ni(2) and four equivalent Cu(1) atoms. In the third Al site, Al(3) is bonded in a body-centered cubic geometry to four equivalent Cu(1) and four equivalent Cu(2) atoms. In the fourth Al site, Al(4) is bonded in a 9-coordinate geometry to one Ni(1), four equivalent Cu(2), and four equivalent Cu(3) atoms.