Ni15Cu4Ga is alpha La-derived structured and crystallizes in the tetragonal P4/mmm space group. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to eight equivalent Ni(4) and four equivalent Ga(1) atoms to form NiGa4Ni8 cuboctahedra that share corners with four equivalent Ni(1)Ga4Ni8 cuboctahedra, corners with eight equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with eight equivalent Cu(1)Ni12 cuboctahedra, edges with sixteen equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(1)Ga4Ni8 cuboctahedra, faces with four equivalent Ga(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to four equivalent Ni(4), four equivalent Ni(5), and four equivalent Cu(1) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Cu4Ni8 cuboctahedra, corners with four equivalent Ni(3)Cu4Ni8 cuboctahedra, corners with four equivalent Ni(1)Ga4Ni8 cuboctahedra, edges with four equivalent Cu(2)Ni12 cuboctahedra, edges with four equivalent Ga(1)Ni12 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra,  a faceface with one Ni(3)Cu4Ni8 cuboctahedra,  a faceface with one Ni(1)Ga4Ni8 cuboctahedra, faces with four equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, and faces with four equivalent Cu(1)Ni12 cuboctahedra. In the third Ni site, Ni(3) is bonded to four equivalent Ni(5), four equivalent Ni(6), and four equivalent Cu(2) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Cu4Ni8 cuboctahedra, corners with eight equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with four equivalent Cu(1)Ni12 cuboctahedra, edges with four equivalent Cu(2)Ni12 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(6)Cu4Ni8 cuboctahedra,  a faceface with one Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(6)Cu4Ni8 cuboctahedra, faces with four equivalent Cu(2)Ni12 cuboctahedra, and faces with five equivalent Ni(3)Cu4Ni8 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(4), two equivalent Cu(1), and two equivalent Ga(1) atoms to form NiGa2Cu2Ni8 cuboctahedra that share corners with four equivalent Ni(5)Cu4Ni8 cuboctahedra, corners with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, edges with four equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, edges with four equivalent Ni(1)Ga4Ni8 cuboctahedra, edges with four equivalent Cu(1)Ni12 cuboctahedra, edges with four equivalent Ga(1)Ni12 cuboctahedra,  a faceface with one Ni(5)Cu4Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with two equivalent Ni(1)Ga4Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with two equivalent Ga(1)Ni12 cuboctahedra, and faces with nine equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra. In the fifth Ni site, Ni(5) is bonded to two equivalent Ni(2), two equivalent Ni(3), four equivalent Ni(5), two equivalent Cu(1), and two equivalent Cu(2) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(5)Cu4Ni8 cuboctahedra, corners with four equivalent Ni(6)Cu4Ni8 cuboctahedra, corners with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, edges with four equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(6)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, edges with four equivalent Cu(1)Ni12 cuboctahedra, edges with four equivalent Cu(2)Ni12 cuboctahedra,  a faceface with one Ni(6)Cu4Ni8 cuboctahedra,  a faceface with one Ni(4)Ga2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with two equivalent Ni(3)Cu4Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with two equivalent Cu(2)Ni12 cuboctahedra, and faces with eight equivalent Ni(5)Cu4Ni8 cuboctahedra. In the sixth Ni site, Ni(6) is bonded to four equivalent Ni(3), four equivalent Ni(6), and four equivalent Cu(2) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(6)Cu4Ni8 cuboctahedra, corners with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Cu(2)Ni12 cuboctahedra, faces with two equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(3)Cu4Ni8 cuboctahedra, faces with four equivalent Cu(2)Ni12 cuboctahedra, and faces with eight equivalent Ni(6)Cu4Ni8 cuboctahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent Ni(2), four equivalent Ni(4), and four equivalent Ni(5) atoms to form CuNi12 cuboctahedra that share corners with four equivalent Cu(1)Ni12 cuboctahedra, corners with four equivalent Cu(2)Ni12 cuboctahedra, corners with four equivalent Ga(1)Ni12 cuboctahedra, edges with four equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(1)Ga4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra,  a faceface with one Cu(2)Ni12 cuboctahedra,  a faceface with one Ga(1)Ni12 cuboctahedra, faces with four equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, and faces with four equivalent Cu(1)Ni12 cuboctahedra. In the second Cu site, Cu(2) is bonded to four equivalent Ni(3), four equivalent Ni(5), and four equivalent Ni(6) atoms to form CuNi12 cuboctahedra that share corners with four equivalent Cu(1)Ni12 cuboctahedra, corners with eight equivalent Cu(2)Ni12 cuboctahedra, edges with four equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(6)Cu4Ni8 cuboctahedra,  a faceface with one Cu(1)Ni12 cuboctahedra, faces with four equivalent Ni(3)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(6)Cu4Ni8 cuboctahedra, and faces with five equivalent Cu(2)Ni12 cuboctahedra. Ga(1) is bonded to four equivalent Ni(1) and eight equivalent Ni(4) atoms to form GaNi12 cuboctahedra that share corners with four equivalent Ga(1)Ni12 cuboctahedra, corners with eight equivalent Cu(1)Ni12 cuboctahedra, edges with eight equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with sixteen equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with four equivalent Ni(1)Ga4Ni8 cuboctahedra, faces with four equivalent Ga(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra.
Ni15Cu4Ga is alpha La-derived structured and crystallizes in the tetragonal P4/mmm space group. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to eight equivalent Ni(4) and four equivalent Ga(1) atoms to form NiGa4Ni8 cuboctahedra that share corners with four equivalent Ni(1)Ga4Ni8 cuboctahedra, corners with eight equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with eight equivalent Cu(1)Ni12 cuboctahedra, edges with sixteen equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(1)Ga4Ni8 cuboctahedra, faces with four equivalent Ga(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra. All Ni(1)-Ni(4) bond lengths are 2.51 Å. All Ni(1)-Ga(1) bond lengths are 2.51 Å. In the second Ni site, Ni(2) is bonded to four equivalent Ni(4), four equivalent Ni(5), and four equivalent Cu(1) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Cu4Ni8 cuboctahedra, corners with four equivalent Ni(3)Cu4Ni8 cuboctahedra, corners with four equivalent Ni(1)Ga4Ni8 cuboctahedra, edges with four equivalent Cu(2)Ni12 cuboctahedra, edges with four equivalent Ga(1)Ni12 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra,  a faceface with one Ni(3)Cu4Ni8 cuboctahedra,  a faceface with one Ni(1)Ga4Ni8 cuboctahedra, faces with four equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, and faces with four equivalent Cu(1)Ni12 cuboctahedra. All Ni(2)-Ni(4) bond lengths are 2.50 Å. All Ni(2)-Ni(5) bond lengths are 2.50 Å. All Ni(2)-Cu(1) bond lengths are 2.51 Å. In the third Ni site, Ni(3) is bonded to four equivalent Ni(5), four equivalent Ni(6), and four equivalent Cu(2) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Cu4Ni8 cuboctahedra, corners with eight equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with four equivalent Cu(1)Ni12 cuboctahedra, edges with four equivalent Cu(2)Ni12 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(6)Cu4Ni8 cuboctahedra,  a faceface with one Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(6)Cu4Ni8 cuboctahedra, faces with four equivalent Cu(2)Ni12 cuboctahedra, and faces with five equivalent Ni(3)Cu4Ni8 cuboctahedra. All Ni(3)-Ni(5) bond lengths are 2.50 Å. All Ni(3)-Ni(6) bond lengths are 2.50 Å. All Ni(3)-Cu(2) bond lengths are 2.51 Å. In the fourth Ni site, Ni(4) is bonded to two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(4), two equivalent Cu(1), and two equivalent Ga(1) atoms to form NiGa2Cu2Ni8 cuboctahedra that share corners with four equivalent Ni(5)Cu4Ni8 cuboctahedra, corners with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, edges with four equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, edges with four equivalent Ni(1)Ga4Ni8 cuboctahedra, edges with four equivalent Cu(1)Ni12 cuboctahedra, edges with four equivalent Ga(1)Ni12 cuboctahedra,  a faceface with one Ni(5)Cu4Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with two equivalent Ni(1)Ga4Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with two equivalent Ga(1)Ni12 cuboctahedra, and faces with nine equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra. All Ni(4)-Ni(4) bond lengths are 2.51 Å. Both Ni(4)-Cu(1) bond lengths are 2.50 Å. Both Ni(4)-Ga(1) bond lengths are 2.51 Å. In the fifth Ni site, Ni(5) is bonded to two equivalent Ni(2), two equivalent Ni(3), four equivalent Ni(5), two equivalent Cu(1), and two equivalent Cu(2) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(5)Cu4Ni8 cuboctahedra, corners with four equivalent Ni(6)Cu4Ni8 cuboctahedra, corners with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, edges with four equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(6)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, edges with four equivalent Cu(1)Ni12 cuboctahedra, edges with four equivalent Cu(2)Ni12 cuboctahedra,  a faceface with one Ni(6)Cu4Ni8 cuboctahedra,  a faceface with one Ni(4)Ga2Cu2Ni8 cuboctahedra, faces with two equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with two equivalent Ni(3)Cu4Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with two equivalent Cu(2)Ni12 cuboctahedra, and faces with eight equivalent Ni(5)Cu4Ni8 cuboctahedra. All Ni(5)-Ni(5) bond lengths are 2.51 Å. Both Ni(5)-Cu(1) bond lengths are 2.50 Å. Both Ni(5)-Cu(2) bond lengths are 2.50 Å. In the sixth Ni site, Ni(6) is bonded to four equivalent Ni(3), four equivalent Ni(6), and four equivalent Cu(2) atoms to form NiCu4Ni8 cuboctahedra that share corners with four equivalent Ni(6)Cu4Ni8 cuboctahedra, corners with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Cu(2)Ni12 cuboctahedra, faces with two equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(3)Cu4Ni8 cuboctahedra, faces with four equivalent Cu(2)Ni12 cuboctahedra, and faces with eight equivalent Ni(6)Cu4Ni8 cuboctahedra. All Ni(6)-Ni(6) bond lengths are 2.51 Å. All Ni(6)-Cu(2) bond lengths are 2.50 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent Ni(2), four equivalent Ni(4), and four equivalent Ni(5) atoms to form CuNi12 cuboctahedra that share corners with four equivalent Cu(1)Ni12 cuboctahedra, corners with four equivalent Cu(2)Ni12 cuboctahedra, corners with four equivalent Ga(1)Ni12 cuboctahedra, edges with four equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(1)Ga4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra,  a faceface with one Cu(2)Ni12 cuboctahedra,  a faceface with one Ga(1)Ni12 cuboctahedra, faces with four equivalent Ni(2)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, and faces with four equivalent Cu(1)Ni12 cuboctahedra. In the second Cu site, Cu(2) is bonded to four equivalent Ni(3), four equivalent Ni(5), and four equivalent Ni(6) atoms to form CuNi12 cuboctahedra that share corners with four equivalent Cu(1)Ni12 cuboctahedra, corners with eight equivalent Cu(2)Ni12 cuboctahedra, edges with four equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with four equivalent Ni(3)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(5)Cu4Ni8 cuboctahedra, edges with eight equivalent Ni(6)Cu4Ni8 cuboctahedra,  a faceface with one Cu(1)Ni12 cuboctahedra, faces with four equivalent Ni(3)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(5)Cu4Ni8 cuboctahedra, faces with four equivalent Ni(6)Cu4Ni8 cuboctahedra, and faces with five equivalent Cu(2)Ni12 cuboctahedra. Ga(1) is bonded to four equivalent Ni(1) and eight equivalent Ni(4) atoms to form GaNi12 cuboctahedra that share corners with four equivalent Ga(1)Ni12 cuboctahedra, corners with eight equivalent Cu(1)Ni12 cuboctahedra, edges with eight equivalent Ni(2)Cu4Ni8 cuboctahedra, edges with sixteen equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra, faces with two equivalent Cu(1)Ni12 cuboctahedra, faces with four equivalent Ni(1)Ga4Ni8 cuboctahedra, faces with four equivalent Ga(1)Ni12 cuboctahedra, and faces with eight equivalent Ni(4)Ga2Cu2Ni8 cuboctahedra.