CoCrTa crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 16-coordinate geometry to one Ta(1); three Ta(2,2); one Cr(3); two equivalent Cr(1); two equivalent Cr(2); three equivalent Co(1); and four equivalent Co(2) atoms. In the second Ta site, Ta(2) is bonded in a 16-coordinate geometry to one Ta(2), three equivalent Ta(1), one Cr(1), two equivalent Cr(3), four equivalent Cr(2), two equivalent Co(2), and three equivalent Co(1) atoms. In the third Ta site, Ta(2) is bonded in a 16-coordinate geometry to one Ta(2), three equivalent Ta(1), one Cr(1), two equivalent Cr(3), four equivalent Cr(2), two equivalent Co(2), and three equivalent Co(1) atoms. In the fourth Ta site, Ta(1) is bonded in a 16-coordinate geometry to one Ta(1); three Ta(2,2); one Cr(3); two equivalent Cr(1); two equivalent Cr(2); three equivalent Co(1); and four equivalent Co(2) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent Ta(2); four Ta(1,1); two equivalent Co(1); and four equivalent Co(2) atoms to form distorted CrTa6Co6 cuboctahedra that share corners with two equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Cr(1)Ta6Co6 cuboctahedra, corners with four equivalent Co(1)Ta6Cr4Co2 cuboctahedra, corners with eight equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, edges with two equivalent Cr(1)Ta6Co6 cuboctahedra, edges with four equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, faces with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, faces with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra, and faces with eight equivalent Co(2)Ta6Cr2Co4 cuboctahedra. In the second Cr site, Cr(2) is bonded to two equivalent Ta(1); four Ta(2,2); two equivalent Cr(2); two equivalent Cr(3); and two equivalent Co(1) atoms to form CrTa6Cr4Co2 cuboctahedra that share corners with four equivalent Cr(1)Ta6Co6 cuboctahedra, corners with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Co(1)Ta6Cr4Co2 cuboctahedra, corners with six equivalent Co(2)Ta6Cr2Co4 cuboctahedra, edges with two equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, edges with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, faces with two equivalent Cr(1)Ta6Co6 cuboctahedra, faces with two equivalent Co(2)Ta6Cr2Co4 cuboctahedra, faces with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, faces with four equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, and faces with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra. In the third Cr site, Cr(3) is bonded to two equivalent Ta(1), four equivalent Ta(2), four equivalent Cr(2), and two equivalent Co(1) atoms to form CrTa6Cr4Co2 cuboctahedra that share corners with two equivalent Cr(1)Ta6Co6 cuboctahedra, corners with four equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Co(1)Ta6Cr4Co2 cuboctahedra, corners with eight equivalent Co(2)Ta6Cr2Co4 cuboctahedra, edges with two equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, edges with four equivalent Cr(1)Ta6Co6 cuboctahedra, faces with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, faces with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra, and faces with eight equivalent Cr(2)Ta6Cr4Co2 cuboctahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent Ta(1); three Ta(2,2); one Cr(1); one Cr(3); two equivalent Cr(2); and two equivalent Co(2) atoms to form CoTa6Cr4Co2 cuboctahedra that share corners with two equivalent Cr(1)Ta6Co6 cuboctahedra, corners with two equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, edges with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra, faces with two equivalent Co(1)Ta6Cr4Co2 cuboctahedra, faces with three equivalent Cr(1)Ta6Co6 cuboctahedra, faces with three equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, faces with six equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, and faces with six equivalent Co(2)Ta6Cr2Co4 cuboctahedra. In the second Co site, Co(2) is bonded to two equivalent Ta(2); four Ta(1,1); two equivalent Cr(1); two equivalent Co(1); and two equivalent Co(2) atoms to form distorted CoTa6Cr2Co4 cuboctahedra that share corners with four equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, corners with four equivalent Co(1)Ta6Cr4Co2 cuboctahedra, corners with six equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, edges with two equivalent Co(2)Ta6Cr2Co4 cuboctahedra, edges with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, faces with two equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, faces with two equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, faces with four equivalent Cr(1)Ta6Co6 cuboctahedra, faces with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, and faces with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra.
CoCrTa crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 16-coordinate geometry to one Ta(1); three Ta(2,2); one Cr(3); two equivalent Cr(1); two equivalent Cr(2); three equivalent Co(1); and four equivalent Co(2) atoms. The Ta(1)-Ta(1) bond length is 2.92 Å. There is one shorter (2.90 Å) and two longer (2.94 Å) Ta(1)-Ta(2,2) bond lengths. The Ta(1)-Cr(3) bond length is 2.84 Å. Both Ta(1)-Cr(1) bond lengths are 2.81 Å. Both Ta(1)-Cr(2) bond lengths are 2.86 Å. There is one shorter (2.74 Å) and two longer (2.81 Å) Ta(1)-Co(1) bond lengths. There are two shorter (2.72 Å) and two longer (2.85 Å) Ta(1)-Co(2) bond lengths. In the second Ta site, Ta(2) is bonded in a 16-coordinate geometry to one Ta(2), three equivalent Ta(1), one Cr(1), two equivalent Cr(3), four equivalent Cr(2), two equivalent Co(2), and three equivalent Co(1) atoms. The Ta(2)-Ta(2) bond length is 3.01 Å. The Ta(2)-Cr(1) bond length is 2.85 Å. Both Ta(2)-Cr(3) bond lengths are 2.83 Å. There are two shorter (2.79 Å) and two longer (2.81 Å) Ta(2)-Cr(2) bond lengths. Both Ta(2)-Co(2) bond lengths are 2.80 Å. There are two shorter (2.79 Å) and one longer (2.81 Å) Ta(2)-Co(1) bond length. In the third Ta site, Ta(2) is bonded in a 16-coordinate geometry to one Ta(2), three equivalent Ta(1), one Cr(1), two equivalent Cr(3), four equivalent Cr(2), two equivalent Co(2), and three equivalent Co(1) atoms. The Ta(2)-Ta(2) bond length is 3.01 Å. The Ta(2)-Cr(1) bond length is 2.85 Å. Both Ta(2)-Cr(3) bond lengths are 2.83 Å. There are two shorter (2.79 Å) and two longer (2.81 Å) Ta(2)-Cr(2) bond lengths. Both Ta(2)-Co(2) bond lengths are 2.80 Å. There are two shorter (2.79 Å) and one longer (2.81 Å) Ta(2)-Co(1) bond length. In the fourth Ta site, Ta(1) is bonded in a 16-coordinate geometry to one Ta(1); three Ta(2,2); one Cr(3); two equivalent Cr(1); two equivalent Cr(2); three equivalent Co(1); and four equivalent Co(2) atoms. The Ta(1)-Ta(1) bond length is 2.92 Å. There is one shorter (2.90 Å) and two longer (2.94 Å) Ta(1)-Ta(2,2) bond lengths. The Ta(1)-Cr(3) bond length is 2.84 Å. Both Ta(1)-Cr(1) bond lengths are 2.81 Å. Both Ta(1)-Cr(2) bond lengths are 2.86 Å. There is one shorter (2.74 Å) and two longer (2.81 Å) Ta(1)-Co(1) bond lengths. There are two shorter (2.72 Å) and two longer (2.85 Å) Ta(1)-Co(2) bond lengths. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent Ta(2); four Ta(1,1); two equivalent Co(1); and four equivalent Co(2) atoms to form distorted CrTa6Co6 cuboctahedra that share corners with two equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Cr(1)Ta6Co6 cuboctahedra, corners with four equivalent Co(1)Ta6Cr4Co2 cuboctahedra, corners with eight equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, edges with two equivalent Cr(1)Ta6Co6 cuboctahedra, edges with four equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, faces with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, faces with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra, and faces with eight equivalent Co(2)Ta6Cr2Co4 cuboctahedra. Both Cr(1)-Co(1) bond lengths are 2.35 Å. There are two shorter (2.31 Å) and two longer (2.43 Å) Cr(1)-Co(2) bond lengths. In the second Cr site, Cr(2) is bonded to two equivalent Ta(1); four Ta(2,2); two equivalent Cr(2); two equivalent Cr(3); and two equivalent Co(1) atoms to form CrTa6Cr4Co2 cuboctahedra that share corners with four equivalent Cr(1)Ta6Co6 cuboctahedra, corners with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Co(1)Ta6Cr4Co2 cuboctahedra, corners with six equivalent Co(2)Ta6Cr2Co4 cuboctahedra, edges with two equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, edges with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, faces with two equivalent Cr(1)Ta6Co6 cuboctahedra, faces with two equivalent Co(2)Ta6Cr2Co4 cuboctahedra, faces with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, faces with four equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, and faces with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra. There is one shorter (2.35 Å) and one longer (2.44 Å) Cr(2)-Cr(2) bond length. There is one shorter (2.30 Å) and one longer (2.43 Å) Cr(2)-Cr(3) bond length. Both Cr(2)-Co(1) bond lengths are 2.49 Å. In the third Cr site, Cr(3) is bonded to two equivalent Ta(1), four equivalent Ta(2), four equivalent Cr(2), and two equivalent Co(1) atoms to form CrTa6Cr4Co2 cuboctahedra that share corners with two equivalent Cr(1)Ta6Co6 cuboctahedra, corners with four equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Co(1)Ta6Cr4Co2 cuboctahedra, corners with eight equivalent Co(2)Ta6Cr2Co4 cuboctahedra, edges with two equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, edges with four equivalent Cr(1)Ta6Co6 cuboctahedra, faces with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, faces with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra, and faces with eight equivalent Cr(2)Ta6Cr4Co2 cuboctahedra. Both Cr(3)-Co(1) bond lengths are 2.47 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent Ta(1); three Ta(2,2); one Cr(1); one Cr(3); two equivalent Cr(2); and two equivalent Co(2) atoms to form CoTa6Cr4Co2 cuboctahedra that share corners with two equivalent Cr(1)Ta6Co6 cuboctahedra, corners with two equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, edges with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra, faces with two equivalent Co(1)Ta6Cr4Co2 cuboctahedra, faces with three equivalent Cr(1)Ta6Co6 cuboctahedra, faces with three equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, faces with six equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, and faces with six equivalent Co(2)Ta6Cr2Co4 cuboctahedra. Both Co(1)-Co(2) bond lengths are 2.40 Å. In the second Co site, Co(2) is bonded to two equivalent Ta(2); four Ta(1,1); two equivalent Cr(1); two equivalent Co(1); and two equivalent Co(2) atoms to form distorted CoTa6Cr2Co4 cuboctahedra that share corners with four equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, corners with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, corners with four equivalent Co(1)Ta6Cr4Co2 cuboctahedra, corners with six equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, edges with two equivalent Co(2)Ta6Cr2Co4 cuboctahedra, edges with four equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, faces with two equivalent Cr(2)Ta6Cr4Co2 cuboctahedra, faces with two equivalent Cr(3)Ta6Cr4Co2 cuboctahedra, faces with four equivalent Cr(1)Ta6Co6 cuboctahedra, faces with four equivalent Co(2)Ta6Cr2Co4 cuboctahedra, and faces with six equivalent Co(1)Ta6Cr4Co2 cuboctahedra. There is one shorter (2.37 Å) and one longer (2.43 Å) Co(2)-Co(2) bond length.