ZrCoSi is Frank-Kasper $\mu$ Phase-derived structured and crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 16-coordinate geometry to one Zr(1), three equivalent Zr(2), three equivalent Co(1), four equivalent Co(2), one Si(3), two equivalent Si(1), and two equivalent Si(2) atoms. In the second Zr site, Zr(2) is bonded in a 12-coordinate geometry to three equivalent Zr(1), two equivalent Co(2), three equivalent Co(1), one Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent Zr(1), three equivalent Zr(2), two equivalent Co(2), one Si(1), one Si(3), and two equivalent Si(2) atoms to form distorted CoZr6Co2Si4 cuboctahedra that share corners with two equivalent Si(3)Zr6Co2Si4 cuboctahedra, corners with two equivalent Si(1)Zr6Co6 cuboctahedra, corners with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, corners with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, edges with six equivalent Co(1)Zr6Co2Si4 cuboctahedra, faces with two equivalent Co(1)Zr6Co2Si4 cuboctahedra, faces with three equivalent Si(3)Zr6Co2Si4 cuboctahedra, faces with three equivalent Si(1)Zr6Co6 cuboctahedra, faces with six equivalent Co(2)Zr6Co4Si2 cuboctahedra, and faces with six equivalent Si(2)Zr6Co2Si4 cuboctahedra. In the second Co site, Co(2) is bonded to two equivalent Zr(2), four equivalent Zr(1), two equivalent Co(1), two equivalent Co(2), and two equivalent Si(1) atoms to form CoZr6Co4Si2 cuboctahedra that share corners with four equivalent Co(1)Zr6Co2Si4 cuboctahedra, corners with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, corners with four equivalent Si(3)Zr6Co2Si4 cuboctahedra, corners with six equivalent Si(2)Zr6Co2Si4 cuboctahedra, edges with two equivalent Co(2)Zr6Co4Si2 cuboctahedra, edges with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, faces with two equivalent Si(2)Zr6Co2Si4 cuboctahedra, faces with two equivalent Si(3)Zr6Co2Si4 cuboctahedra, faces with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, faces with four equivalent Si(1)Zr6Co6 cuboctahedra, and faces with six equivalent Co(1)Zr6Co2Si4 cuboctahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent Zr(2), four equivalent Zr(1), two equivalent Co(1), and four equivalent Co(2) atoms to form SiZr6Co6 cuboctahedra that share corners with two equivalent Si(3)Zr6Co2Si4 cuboctahedra, corners with four equivalent Co(1)Zr6Co2Si4 cuboctahedra, corners with four equivalent Si(1)Zr6Co6 cuboctahedra, corners with eight equivalent Si(2)Zr6Co2Si4 cuboctahedra, edges with two equivalent Si(1)Zr6Co6 cuboctahedra, edges with four equivalent Si(3)Zr6Co2Si4 cuboctahedra, faces with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, faces with six equivalent Co(1)Zr6Co2Si4 cuboctahedra, and faces with eight equivalent Co(2)Zr6Co4Si2 cuboctahedra. In the second Si site, Si(2) is bonded to two equivalent Zr(1), four equivalent Zr(2), two equivalent Co(1), two equivalent Si(2), and two equivalent Si(3) atoms to form distorted SiZr6Co2Si4 cuboctahedra that share corners with four equivalent Co(1)Zr6Co2Si4 cuboctahedra, corners with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, corners with four equivalent Si(1)Zr6Co6 cuboctahedra, corners with six equivalent Co(2)Zr6Co4Si2 cuboctahedra, edges with two equivalent Si(2)Zr6Co2Si4 cuboctahedra, edges with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, faces with two equivalent Co(2)Zr6Co4Si2 cuboctahedra, faces with two equivalent Si(1)Zr6Co6 cuboctahedra, faces with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, faces with four equivalent Si(3)Zr6Co2Si4 cuboctahedra, and faces with six equivalent Co(1)Zr6Co2Si4 cuboctahedra. In the third Si site, Si(3) is bonded to two equivalent Zr(1), four equivalent Zr(2), two equivalent Co(1), and four equivalent Si(2) atoms to form SiZr6Co2Si4 cuboctahedra that share corners with two equivalent Si(1)Zr6Co6 cuboctahedra, corners with four equivalent Co(1)Zr6Co2Si4 cuboctahedra, corners with four equivalent Si(3)Zr6Co2Si4 cuboctahedra, corners with eight equivalent Co(2)Zr6Co4Si2 cuboctahedra, edges with two equivalent Si(3)Zr6Co2Si4 cuboctahedra, edges with four equivalent Si(1)Zr6Co6 cuboctahedra, faces with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, faces with six equivalent Co(1)Zr6Co2Si4 cuboctahedra, and faces with eight equivalent Si(2)Zr6Co2Si4 cuboctahedra.
ZrCoSi is Frank-Kasper $\mu$ Phase-derived structured and crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 16-coordinate geometry to one Zr(1), three equivalent Zr(2), three equivalent Co(1), four equivalent Co(2), one Si(3), two equivalent Si(1), and two equivalent Si(2) atoms. The Zr(1)-Zr(1) bond length is 2.86 Å. There is one shorter (2.97 Å) and two longer (3.08 Å) Zr(1)-Zr(2) bond lengths. There are two shorter (2.96 Å) and one longer (3.03 Å) Zr(1)-Co(1) bond length. There are two shorter (2.82 Å) and two longer (2.93 Å) Zr(1)-Co(2) bond lengths. The Zr(1)-Si(3) bond length is 2.91 Å. Both Zr(1)-Si(1) bond lengths are 2.92 Å. Both Zr(1)-Si(2) bond lengths are 2.90 Å. In the second Zr site, Zr(2) is bonded in a 12-coordinate geometry to three equivalent Zr(1), two equivalent Co(2), three equivalent Co(1), one Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. Both Zr(2)-Co(2) bond lengths are 2.76 Å. There is one shorter (2.82 Å) and two longer (2.95 Å) Zr(2)-Co(1) bond lengths. The Zr(2)-Si(1) bond length is 2.85 Å. Both Zr(2)-Si(3) bond lengths are 3.01 Å. There are two shorter (2.94 Å) and two longer (2.98 Å) Zr(2)-Si(2) bond lengths. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent Zr(1), three equivalent Zr(2), two equivalent Co(2), one Si(1), one Si(3), and two equivalent Si(2) atoms to form distorted CoZr6Co2Si4 cuboctahedra that share corners with two equivalent Si(3)Zr6Co2Si4 cuboctahedra, corners with two equivalent Si(1)Zr6Co6 cuboctahedra, corners with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, corners with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, edges with six equivalent Co(1)Zr6Co2Si4 cuboctahedra, faces with two equivalent Co(1)Zr6Co2Si4 cuboctahedra, faces with three equivalent Si(3)Zr6Co2Si4 cuboctahedra, faces with three equivalent Si(1)Zr6Co6 cuboctahedra, faces with six equivalent Co(2)Zr6Co4Si2 cuboctahedra, and faces with six equivalent Si(2)Zr6Co2Si4 cuboctahedra. Both Co(1)-Co(2) bond lengths are 2.62 Å. The Co(1)-Si(1) bond length is 2.45 Å. The Co(1)-Si(3) bond length is 2.37 Å. Both Co(1)-Si(2) bond lengths are 2.34 Å. In the second Co site, Co(2) is bonded to two equivalent Zr(2), four equivalent Zr(1), two equivalent Co(1), two equivalent Co(2), and two equivalent Si(1) atoms to form CoZr6Co4Si2 cuboctahedra that share corners with four equivalent Co(1)Zr6Co2Si4 cuboctahedra, corners with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, corners with four equivalent Si(3)Zr6Co2Si4 cuboctahedra, corners with six equivalent Si(2)Zr6Co2Si4 cuboctahedra, edges with two equivalent Co(2)Zr6Co4Si2 cuboctahedra, edges with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, faces with two equivalent Si(2)Zr6Co2Si4 cuboctahedra, faces with two equivalent Si(3)Zr6Co2Si4 cuboctahedra, faces with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, faces with four equivalent Si(1)Zr6Co6 cuboctahedra, and faces with six equivalent Co(1)Zr6Co2Si4 cuboctahedra. There is one shorter (2.52 Å) and one longer (2.57 Å) Co(2)-Co(2) bond length. There is one shorter (2.44 Å) and one longer (2.54 Å) Co(2)-Si(1) bond length. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent Zr(2), four equivalent Zr(1), two equivalent Co(1), and four equivalent Co(2) atoms to form SiZr6Co6 cuboctahedra that share corners with two equivalent Si(3)Zr6Co2Si4 cuboctahedra, corners with four equivalent Co(1)Zr6Co2Si4 cuboctahedra, corners with four equivalent Si(1)Zr6Co6 cuboctahedra, corners with eight equivalent Si(2)Zr6Co2Si4 cuboctahedra, edges with two equivalent Si(1)Zr6Co6 cuboctahedra, edges with four equivalent Si(3)Zr6Co2Si4 cuboctahedra, faces with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, faces with six equivalent Co(1)Zr6Co2Si4 cuboctahedra, and faces with eight equivalent Co(2)Zr6Co4Si2 cuboctahedra. In the second Si site, Si(2) is bonded to two equivalent Zr(1), four equivalent Zr(2), two equivalent Co(1), two equivalent Si(2), and two equivalent Si(3) atoms to form distorted SiZr6Co2Si4 cuboctahedra that share corners with four equivalent Co(1)Zr6Co2Si4 cuboctahedra, corners with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, corners with four equivalent Si(1)Zr6Co6 cuboctahedra, corners with six equivalent Co(2)Zr6Co4Si2 cuboctahedra, edges with two equivalent Si(2)Zr6Co2Si4 cuboctahedra, edges with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, faces with two equivalent Co(2)Zr6Co4Si2 cuboctahedra, faces with two equivalent Si(1)Zr6Co6 cuboctahedra, faces with four equivalent Si(2)Zr6Co2Si4 cuboctahedra, faces with four equivalent Si(3)Zr6Co2Si4 cuboctahedra, and faces with six equivalent Co(1)Zr6Co2Si4 cuboctahedra. There is one shorter (2.49 Å) and one longer (2.60 Å) Si(2)-Si(2) bond length. There is one shorter (2.46 Å) and one longer (2.52 Å) Si(2)-Si(3) bond length. In the third Si site, Si(3) is bonded to two equivalent Zr(1), four equivalent Zr(2), two equivalent Co(1), and four equivalent Si(2) atoms to form SiZr6Co2Si4 cuboctahedra that share corners with two equivalent Si(1)Zr6Co6 cuboctahedra, corners with four equivalent Co(1)Zr6Co2Si4 cuboctahedra, corners with four equivalent Si(3)Zr6Co2Si4 cuboctahedra, corners with eight equivalent Co(2)Zr6Co4Si2 cuboctahedra, edges with two equivalent Si(3)Zr6Co2Si4 cuboctahedra, edges with four equivalent Si(1)Zr6Co6 cuboctahedra, faces with four equivalent Co(2)Zr6Co4Si2 cuboctahedra, faces with six equivalent Co(1)Zr6Co2Si4 cuboctahedra, and faces with eight equivalent Si(2)Zr6Co2Si4 cuboctahedra.