Mn4Ni5Si3 is Hexagonal Laves-derived structured and crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 16-coordinate geometry to one Mn(1); three Mn(2,2); two equivalent Ni(1); two equivalent Ni(2); four equivalent Ni(3); one Si(2); and three equivalent Si(1) atoms. In the second Mn site, Mn(2) is bonded in a 16-coordinate geometry to one Mn(2), three equivalent Mn(1), one Ni(2), two equivalent Ni(3), four equivalent Ni(1), two equivalent Si(2), and three equivalent Si(1) atoms. In the third Mn site, Mn(1) is bonded in a 16-coordinate geometry to one Mn(1), three equivalent Mn(2), two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(3), one Si(2), and three equivalent Si(1) atoms. In the fourth Mn site, Mn(2) is bonded in a 16-coordinate geometry to one Mn(2), three equivalent Mn(1), one Ni(2), two equivalent Ni(3), four equivalent Ni(1), two equivalent Si(2), and three equivalent Si(1) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two Mn(1,1); four Mn(2,2); two equivalent Ni(1); two equivalent Si(1); and two equivalent Si(2) atoms to form NiMn6Si4Ni2 cuboctahedra that share corners with four equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, corners with four equivalent Si(1)Mn6SiNi5 cuboctahedra, corners with six equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, edges with two equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, edges with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, faces with two equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, faces with two equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, faces with four equivalent Si(2)Mn6Si2Ni4 cuboctahedra, and faces with six equivalent Si(1)Mn6SiNi5 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Mn(2), four equivalent Mn(1), four equivalent Ni(3), and two equivalent Si(1) atoms to form NiMn6Si2Ni4 cuboctahedra that share corners with two equivalent Si(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(1)Mn6SiNi5 cuboctahedra, corners with eight equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, edges with two equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, edges with four equivalent Si(2)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, faces with six equivalent Si(1)Mn6SiNi5 cuboctahedra, and faces with eight equivalent Ni(3)Mn6Si2Ni4 cuboctahedra. In the third Ni site, Ni(3) is bonded to two equivalent Mn(2); four Mn(1,1); two equivalent Ni(2); two equivalent Ni(3); and two equivalent Si(1) atoms to form NiMn6Si2Ni4 cuboctahedra that share corners with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(1)Mn6SiNi5 cuboctahedra, corners with six equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, edges with two equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, edges with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, faces with two equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, faces with two equivalent Si(2)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, and faces with six equivalent Si(1)Mn6SiNi5 cuboctahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to three Mn(1,1); three equivalent Mn(2); one Ni(2); two equivalent Ni(1); two equivalent Ni(3); and one Si(2) atom to form SiMn6SiNi5 cuboctahedra that share corners with two equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, corners with two equivalent Si(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, edges with six equivalent Si(1)Mn6SiNi5 cuboctahedra, faces with two equivalent Si(1)Mn6SiNi5 cuboctahedra, faces with three equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, faces with three equivalent Si(2)Mn6Si2Ni4 cuboctahedra, faces with six equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, and faces with six equivalent Ni(1)Mn6Si4Ni2 cuboctahedra. In the second Si site, Si(2) is bonded to two Mn(1,1); four Mn(2,2); four equivalent Ni(1); and two equivalent Si(1) atoms to form SiMn6Si2Ni4 cuboctahedra that share corners with two equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(1)Mn6SiNi5 cuboctahedra, corners with eight equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, edges with two equivalent Si(2)Mn6Si2Ni4 cuboctahedra, edges with four equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, faces with six equivalent Si(1)Mn6SiNi5 cuboctahedra, and faces with eight equivalent Ni(1)Mn6Si4Ni2 cuboctahedra.
Mn4Ni5Si3 is Hexagonal Laves-derived structured and crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 16-coordinate geometry to one Mn(1); three Mn(2,2); two equivalent Ni(1); two equivalent Ni(2); four equivalent Ni(3); one Si(2); and three equivalent Si(1) atoms. The Mn(1)-Mn(1) bond length is 2.77 Å. There is one shorter (2.88 Å) and two longer (2.89 Å) Mn(1)-Mn(2,2) bond lengths. Both Mn(1)-Ni(1) bond lengths are 2.75 Å. Both Mn(1)-Ni(2) bond lengths are 2.74 Å. There are two shorter (2.73 Å) and two longer (2.74 Å) Mn(1)-Ni(3) bond lengths. The Mn(1)-Si(2) bond length is 2.66 Å. There are two shorter (2.73 Å) and one longer (2.83 Å) Mn(1)-Si(1) bond length. In the second Mn site, Mn(2) is bonded in a 16-coordinate geometry to one Mn(2), three equivalent Mn(1), one Ni(2), two equivalent Ni(3), four equivalent Ni(1), two equivalent Si(2), and three equivalent Si(1) atoms. The Mn(2)-Mn(2) bond length is 2.85 Å. The Mn(2)-Ni(2) bond length is 2.67 Å. Both Mn(2)-Ni(3) bond lengths are 2.69 Å. There are two shorter (2.71 Å) and two longer (2.80 Å) Mn(2)-Ni(1) bond lengths. Both Mn(2)-Si(2) bond lengths are 2.77 Å. There is one shorter (2.68 Å) and two longer (2.82 Å) Mn(2)-Si(1) bond lengths. In the third Mn site, Mn(1) is bonded in a 16-coordinate geometry to one Mn(1), three equivalent Mn(2), two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(3), one Si(2), and three equivalent Si(1) atoms. There is one shorter (2.88 Å) and two longer (2.89 Å) Mn(1)-Mn(2) bond lengths. Both Mn(1)-Ni(1) bond lengths are 2.75 Å. Both Mn(1)-Ni(2) bond lengths are 2.74 Å. There are two shorter (2.73 Å) and two longer (2.74 Å) Mn(1)-Ni(3) bond lengths. The Mn(1)-Si(2) bond length is 2.66 Å. There are two shorter (2.73 Å) and one longer (2.83 Å) Mn(1)-Si(1) bond length. In the fourth Mn site, Mn(2) is bonded in a 16-coordinate geometry to one Mn(2), three equivalent Mn(1), one Ni(2), two equivalent Ni(3), four equivalent Ni(1), two equivalent Si(2), and three equivalent Si(1) atoms. The Mn(2)-Mn(2) bond length is 2.85 Å. The Mn(2)-Ni(2) bond length is 2.67 Å. Both Mn(2)-Ni(3) bond lengths are 2.69 Å. There are two shorter (2.71 Å) and two longer (2.80 Å) Mn(2)-Ni(1) bond lengths. Both Mn(2)-Si(2) bond lengths are 2.77 Å. There is one shorter (2.68 Å) and two longer (2.82 Å) Mn(2)-Si(1) bond lengths. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two Mn(1,1); four Mn(2,2); two equivalent Ni(1); two equivalent Si(1); and two equivalent Si(2) atoms to form NiMn6Si4Ni2 cuboctahedra that share corners with four equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, corners with four equivalent Si(1)Mn6SiNi5 cuboctahedra, corners with six equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, edges with two equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, edges with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, faces with two equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, faces with two equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, faces with four equivalent Si(2)Mn6Si2Ni4 cuboctahedra, and faces with six equivalent Si(1)Mn6SiNi5 cuboctahedra. There is one shorter (2.36 Å) and one longer (2.38 Å) Ni(1)-Ni(1) bond length. Both Ni(1)-Si(1) bond lengths are 2.33 Å. There is one shorter (2.28 Å) and one longer (2.43 Å) Ni(1)-Si(2) bond length. In the second Ni site, Ni(2) is bonded to two equivalent Mn(2), four equivalent Mn(1), four equivalent Ni(3), and two equivalent Si(1) atoms to form NiMn6Si2Ni4 cuboctahedra that share corners with two equivalent Si(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(1)Mn6SiNi5 cuboctahedra, corners with eight equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, edges with two equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, edges with four equivalent Si(2)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, faces with six equivalent Si(1)Mn6SiNi5 cuboctahedra, and faces with eight equivalent Ni(3)Mn6Si2Ni4 cuboctahedra. There are two shorter (2.30 Å) and two longer (2.41 Å) Ni(2)-Ni(3) bond lengths. Both Ni(2)-Si(1) bond lengths are 2.26 Å. In the third Ni site, Ni(3) is bonded to two equivalent Mn(2); four Mn(1,1); two equivalent Ni(2); two equivalent Ni(3); and two equivalent Si(1) atoms to form NiMn6Si2Ni4 cuboctahedra that share corners with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(1)Mn6SiNi5 cuboctahedra, corners with six equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, edges with two equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, edges with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, faces with two equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, faces with two equivalent Si(2)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, and faces with six equivalent Si(1)Mn6SiNi5 cuboctahedra. There is one shorter (2.33 Å) and one longer (2.41 Å) Ni(3)-Ni(3) bond length. Both Ni(3)-Si(1) bond lengths are 2.31 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to three Mn(1,1); three equivalent Mn(2); one Ni(2); two equivalent Ni(1); two equivalent Ni(3); and one Si(2) atom to form SiMn6SiNi5 cuboctahedra that share corners with two equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, corners with two equivalent Si(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Ni(1)Mn6Si4Ni2 cuboctahedra, edges with six equivalent Si(1)Mn6SiNi5 cuboctahedra, faces with two equivalent Si(1)Mn6SiNi5 cuboctahedra, faces with three equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, faces with three equivalent Si(2)Mn6Si2Ni4 cuboctahedra, faces with six equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, and faces with six equivalent Ni(1)Mn6Si4Ni2 cuboctahedra. The Si(1)-Si(2) bond length is 2.49 Å. In the second Si site, Si(2) is bonded to two Mn(1,1); four Mn(2,2); four equivalent Ni(1); and two equivalent Si(1) atoms to form SiMn6Si2Ni4 cuboctahedra that share corners with two equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(2)Mn6Si2Ni4 cuboctahedra, corners with four equivalent Si(1)Mn6SiNi5 cuboctahedra, corners with eight equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, edges with two equivalent Si(2)Mn6Si2Ni4 cuboctahedra, edges with four equivalent Ni(2)Mn6Si2Ni4 cuboctahedra, faces with four equivalent Ni(3)Mn6Si2Ni4 cuboctahedra, faces with six equivalent Si(1)Mn6SiNi5 cuboctahedra, and faces with eight equivalent Ni(1)Mn6Si4Ni2 cuboctahedra.