Nb4CoPt3 crystallizes in the orthorhombic Pmm2 space group. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 8-coordinate geometry to two equivalent Co(1), two equivalent Pt(1), and four equivalent Pt(2) atoms. In the second Nb site, Nb(2) is bonded to two equivalent Nb(2), two equivalent Nb(3), two equivalent Co(1), two equivalent Pt(1), and four equivalent Pt(3) atoms to form distorted NbNb4Co2Pt6 cuboctahedra that share corners with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, corners with four equivalent Pt(1)Nb8Pt4 cuboctahedra, corners with six equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with two equivalent Co(1)Nb8Co2Pt2 cuboctahedra, edges with two equivalent Pt(1)Nb8Pt4 cuboctahedra, edges with four equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, edges with four equivalent Pt(3)Nb8Pt4 cuboctahedra, faces with two equivalent Co(1)Nb8Co2Pt2 cuboctahedra, faces with two equivalent Pt(1)Nb8Pt4 cuboctahedra, faces with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, faces with four equivalent Pt(3)Nb8Pt4 cuboctahedra, and faces with six equivalent Nb(3)Nb2Co4Pt4 cuboctahedra. In the third Nb site, Nb(3) is bonded to two equivalent Nb(2), four equivalent Co(1), two equivalent Pt(2), and two equivalent Pt(3) atoms to form distorted NbNb2Co4Pt4 cuboctahedra that share corners with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, corners with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, corners with six equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, corners with six equivalent Pt(3)Nb8Pt4 cuboctahedra, edges with four equivalent Pt(1)Nb8Pt4 cuboctahedra, faces with two equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, faces with two equivalent Pt(3)Nb8Pt4 cuboctahedra, faces with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, faces with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, and faces with six equivalent Nb(2)Nb4Co2Pt6 cuboctahedra. In the fourth Nb site, Nb(4) is bonded in a 8-coordinate geometry to two equivalent Pt(2), two equivalent Pt(3), and four equivalent Pt(1) atoms. Co(1) is bonded to two equivalent Nb(1), two equivalent Nb(2), four equivalent Nb(3), two equivalent Co(1), and two equivalent Pt(2) atoms to form distorted CoNb8Co2Pt2 cuboctahedra that share corners with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, corners with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, corners with four equivalent Pt(1)Nb8Pt4 cuboctahedra, corners with six equivalent Co(1)Nb8Co2Pt2 cuboctahedra, edges with two equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with two equivalent Pt(1)Nb8Pt4 cuboctahedra, edges with four equivalent Pt(3)Nb8Pt4 cuboctahedra, faces with two equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, faces with two equivalent Pt(3)Nb8Pt4 cuboctahedra, faces with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, faces with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, and faces with six equivalent Pt(2)Nb8Co2Pt2 cuboctahedra. There are three inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to two equivalent Nb(1), two equivalent Nb(2), four equivalent Nb(4), two equivalent Pt(1), and two equivalent Pt(3) atoms to form distorted PtNb8Pt4 cuboctahedra that share corners with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, corners with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, corners with six equivalent Pt(1)Nb8Pt4 cuboctahedra, edges with two equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with two equivalent Co(1)Nb8Co2Pt2 cuboctahedra, edges with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, edges with four equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, faces with two equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, faces with two equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, faces with four equivalent Pt(1)Nb8Pt4 cuboctahedra, and faces with six equivalent Pt(3)Nb8Pt4 cuboctahedra. In the second Pt site, Pt(2) is bonded to two equivalent Nb(3), two equivalent Nb(4), four equivalent Nb(1), two equivalent Co(1), and two equivalent Pt(2) atoms to form distorted PtNb8Co2Pt2 cuboctahedra that share corners with four equivalent Pt(3)Nb8Pt4 cuboctahedra, corners with six equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, corners with six equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, edges with two equivalent Pt(3)Nb8Pt4 cuboctahedra, edges with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with four equivalent Pt(1)Nb8Pt4 cuboctahedra, faces with two equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, faces with two equivalent Pt(1)Nb8Pt4 cuboctahedra, faces with four equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, and faces with six equivalent Co(1)Nb8Co2Pt2 cuboctahedra. In the third Pt site, Pt(3) is bonded to two equivalent Nb(3), two equivalent Nb(4), four equivalent Nb(2), two equivalent Pt(1), and two equivalent Pt(3) atoms to form distorted PtNb8Pt4 cuboctahedra that share corners with four equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, corners with six equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, corners with six equivalent Pt(3)Nb8Pt4 cuboctahedra, edges with two equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, edges with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, faces with two equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, faces with two equivalent Co(1)Nb8Co2Pt2 cuboctahedra, faces with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, faces with four equivalent Pt(3)Nb8Pt4 cuboctahedra, and faces with six equivalent Pt(1)Nb8Pt4 cuboctahedra.
Nb4CoPt3 crystallizes in the orthorhombic Pmm2 space group. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 8-coordinate geometry to two equivalent Co(1), two equivalent Pt(1), and four equivalent Pt(2) atoms. Both Nb(1)-Co(1) bond lengths are 2.78 Å. Both Nb(1)-Pt(1) bond lengths are 2.97 Å. All Nb(1)-Pt(2) bond lengths are 2.78 Å. In the second Nb site, Nb(2) is bonded to two equivalent Nb(2), two equivalent Nb(3), two equivalent Co(1), two equivalent Pt(1), and four equivalent Pt(3) atoms to form distorted NbNb4Co2Pt6 cuboctahedra that share corners with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, corners with four equivalent Pt(1)Nb8Pt4 cuboctahedra, corners with six equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with two equivalent Co(1)Nb8Co2Pt2 cuboctahedra, edges with two equivalent Pt(1)Nb8Pt4 cuboctahedra, edges with four equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, edges with four equivalent Pt(3)Nb8Pt4 cuboctahedra, faces with two equivalent Co(1)Nb8Co2Pt2 cuboctahedra, faces with two equivalent Pt(1)Nb8Pt4 cuboctahedra, faces with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, faces with four equivalent Pt(3)Nb8Pt4 cuboctahedra, and faces with six equivalent Nb(3)Nb2Co4Pt4 cuboctahedra. Both Nb(2)-Nb(2) bond lengths are 2.82 Å. Both Nb(2)-Nb(3) bond lengths are 2.92 Å. Both Nb(2)-Co(1) bond lengths are 2.78 Å. Both Nb(2)-Pt(1) bond lengths are 2.92 Å. All Nb(2)-Pt(3) bond lengths are 2.82 Å. In the third Nb site, Nb(3) is bonded to two equivalent Nb(2), four equivalent Co(1), two equivalent Pt(2), and two equivalent Pt(3) atoms to form distorted NbNb2Co4Pt4 cuboctahedra that share corners with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, corners with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, corners with six equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, corners with six equivalent Pt(3)Nb8Pt4 cuboctahedra, edges with four equivalent Pt(1)Nb8Pt4 cuboctahedra, faces with two equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, faces with two equivalent Pt(3)Nb8Pt4 cuboctahedra, faces with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, faces with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, and faces with six equivalent Nb(2)Nb4Co2Pt6 cuboctahedra. All Nb(3)-Co(1) bond lengths are 2.78 Å. Both Nb(3)-Pt(2) bond lengths are 2.75 Å. Both Nb(3)-Pt(3) bond lengths are 2.94 Å. In the fourth Nb site, Nb(4) is bonded in a 8-coordinate geometry to two equivalent Pt(2), two equivalent Pt(3), and four equivalent Pt(1) atoms. Both Nb(4)-Pt(2) bond lengths are 2.89 Å. Both Nb(4)-Pt(3) bond lengths are 2.86 Å. All Nb(4)-Pt(1) bond lengths are 2.81 Å. Co(1) is bonded to two equivalent Nb(1), two equivalent Nb(2), four equivalent Nb(3), two equivalent Co(1), and two equivalent Pt(2) atoms to form distorted CoNb8Co2Pt2 cuboctahedra that share corners with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, corners with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, corners with four equivalent Pt(1)Nb8Pt4 cuboctahedra, corners with six equivalent Co(1)Nb8Co2Pt2 cuboctahedra, edges with two equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with two equivalent Pt(1)Nb8Pt4 cuboctahedra, edges with four equivalent Pt(3)Nb8Pt4 cuboctahedra, faces with two equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, faces with two equivalent Pt(3)Nb8Pt4 cuboctahedra, faces with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, faces with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, and faces with six equivalent Pt(2)Nb8Co2Pt2 cuboctahedra. Both Co(1)-Co(1) bond lengths are 2.82 Å. Both Co(1)-Pt(2) bond lengths are 2.90 Å. There are three inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to two equivalent Nb(1), two equivalent Nb(2), four equivalent Nb(4), two equivalent Pt(1), and two equivalent Pt(3) atoms to form distorted PtNb8Pt4 cuboctahedra that share corners with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, corners with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, corners with six equivalent Pt(1)Nb8Pt4 cuboctahedra, edges with two equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with two equivalent Co(1)Nb8Co2Pt2 cuboctahedra, edges with four equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, edges with four equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, faces with two equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, faces with two equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, faces with four equivalent Pt(1)Nb8Pt4 cuboctahedra, and faces with six equivalent Pt(3)Nb8Pt4 cuboctahedra. Both Pt(1)-Pt(1) bond lengths are 2.82 Å. Both Pt(1)-Pt(3) bond lengths are 2.90 Å. In the second Pt site, Pt(2) is bonded to two equivalent Nb(3), two equivalent Nb(4), four equivalent Nb(1), two equivalent Co(1), and two equivalent Pt(2) atoms to form distorted PtNb8Co2Pt2 cuboctahedra that share corners with four equivalent Pt(3)Nb8Pt4 cuboctahedra, corners with six equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, corners with six equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, edges with two equivalent Pt(3)Nb8Pt4 cuboctahedra, edges with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with four equivalent Pt(1)Nb8Pt4 cuboctahedra, faces with two equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, faces with two equivalent Pt(1)Nb8Pt4 cuboctahedra, faces with four equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, and faces with six equivalent Co(1)Nb8Co2Pt2 cuboctahedra. Both Pt(2)-Pt(2) bond lengths are 2.82 Å. In the third Pt site, Pt(3) is bonded to two equivalent Nb(3), two equivalent Nb(4), four equivalent Nb(2), two equivalent Pt(1), and two equivalent Pt(3) atoms to form distorted PtNb8Pt4 cuboctahedra that share corners with four equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, corners with six equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, corners with six equivalent Pt(3)Nb8Pt4 cuboctahedra, edges with two equivalent Pt(2)Nb8Co2Pt2 cuboctahedra, edges with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, edges with four equivalent Co(1)Nb8Co2Pt2 cuboctahedra, faces with two equivalent Nb(3)Nb2Co4Pt4 cuboctahedra, faces with two equivalent Co(1)Nb8Co2Pt2 cuboctahedra, faces with four equivalent Nb(2)Nb4Co2Pt6 cuboctahedra, faces with four equivalent Pt(3)Nb8Pt4 cuboctahedra, and faces with six equivalent Pt(1)Nb8Pt4 cuboctahedra. Both Pt(3)-Pt(3) bond lengths are 2.82 Å.