Mg14WSi crystallizes in the orthorhombic Amm2 space group. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), two equivalent Mg(6), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent W(1)Mg10Si2 cuboctahedra, corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Mg8Si2W2 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(6)Mg11Si cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Si(1)Mg10W2 cuboctahedra, and faces with four equivalent Mg(4)Mg12 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(7), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Si(1)Mg10W2 cuboctahedra, corners with six equivalent Mg(2)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Mg8Si2W2 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent W(1)Mg10Si2 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(6)Mg11Si cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent W(1), and two equivalent Si(1) atoms to form distorted MgMg8Si2W2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with six equivalent Mg(3)Mg8Si2W2 cuboctahedra, edges with two equivalent Mg(3)Mg8Si2W2 cuboctahedra, edges with two equivalent W(1)Mg10Si2 cuboctahedra, edges with two equivalent Si(1)Mg10W2 cuboctahedra, edges with four equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg8Si2W2 cuboctahedra, faces with two equivalent W(1)Mg10Si2 cuboctahedra, and faces with two equivalent Si(1)Mg10W2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Mg(3)Mg8Si2W2 cuboctahedra, corners with four equivalent W(1)Mg10Si2 cuboctahedra, corners with four equivalent Si(1)Mg10W2 cuboctahedra, corners with six equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, and faces with two equivalent Mg(3)Mg8Si2W2 cuboctahedra. In the fifth Mg site, Mg(5) is bonded in a 2-coordinate geometry to one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(6), one W(1), and one Si(1) atom. In the sixth Mg site, Mg(6) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(7), four equivalent Mg(5), and one Si(1) atom to form distorted MgMg11Si cuboctahedra that share corners with six equivalent Mg(6)Mg11Si cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Si(1)Mg10W2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(3)Mg8Si2W2 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra,  a faceface with one Si(1)Mg10W2 cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg8Si2W2 cuboctahedra, faces with three equivalent Mg(2)Mg12 cuboctahedra, and faces with three equivalent W(1)Mg10Si2 cuboctahedra. In the seventh Mg site, Mg(7) is bonded in a distorted single-bond geometry to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), and one W(1) atom. W(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Si(1) atoms to form WMg10Si2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent W(1)Mg10Si2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Si(1)Mg10W2 cuboctahedra, edges with four equivalent Mg(3)Mg8Si2W2 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Si(1)Mg10W2 cuboctahedra, faces with four equivalent Mg(3)Mg8Si2W2 cuboctahedra, and faces with six equivalent Mg(6)Mg11Si cuboctahedra. Si(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent W(1) atoms to form SiMg10W2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with six equivalent Si(1)Mg10W2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent W(1)Mg10Si2 cuboctahedra, edges with four equivalent Mg(6)Mg11Si cuboctahedra, edges with four equivalent Mg(3)Mg8Si2W2 cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent W(1)Mg10Si2 cuboctahedra, and faces with four equivalent Mg(3)Mg8Si2W2 cuboctahedra.
Mg14WSi crystallizes in the orthorhombic Amm2 space group. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), two equivalent Mg(6), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent W(1)Mg10Si2 cuboctahedra, corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Mg8Si2W2 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(6)Mg11Si cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Si(1)Mg10W2 cuboctahedra, and faces with four equivalent Mg(4)Mg12 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.03 Å. Both Mg(1)-Mg(6) bond lengths are 3.09 Å. There are two shorter (3.08 Å) and two longer (3.12 Å) Mg(1)-Mg(4) bond lengths. All Mg(1)-Mg(5) bond lengths are 3.19 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(7), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Si(1)Mg10W2 cuboctahedra, corners with six equivalent Mg(2)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Mg8Si2W2 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent W(1)Mg10Si2 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(6)Mg11Si cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.12 Å. There are two shorter (3.09 Å) and two longer (3.11 Å) Mg(2)-Mg(4) bond lengths. All Mg(2)-Mg(5) bond lengths are 3.18 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent W(1), and two equivalent Si(1) atoms to form distorted MgMg8Si2W2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with six equivalent Mg(3)Mg8Si2W2 cuboctahedra, edges with two equivalent Mg(3)Mg8Si2W2 cuboctahedra, edges with two equivalent W(1)Mg10Si2 cuboctahedra, edges with two equivalent Si(1)Mg10W2 cuboctahedra, edges with four equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg8Si2W2 cuboctahedra, faces with two equivalent W(1)Mg10Si2 cuboctahedra, and faces with two equivalent Si(1)Mg10W2 cuboctahedra. Both Mg(3)-Mg(3) bond lengths are 3.03 Å. Both Mg(3)-Mg(5) bond lengths are 3.02 Å. Both Mg(3)-Mg(6) bond lengths are 3.08 Å. Both Mg(3)-Mg(7) bond lengths are 3.04 Å. There is one shorter (3.06 Å) and one longer (3.13 Å) Mg(3)-W(1) bond length. There is one shorter (3.05 Å) and one longer (3.14 Å) Mg(3)-Si(1) bond length. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Mg(3)Mg8Si2W2 cuboctahedra, corners with four equivalent W(1)Mg10Si2 cuboctahedra, corners with four equivalent Si(1)Mg10W2 cuboctahedra, corners with six equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, and faces with two equivalent Mg(3)Mg8Si2W2 cuboctahedra. There is one shorter (3.02 Å) and one longer (3.04 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5) bond lengths are 3.22 Å. Both Mg(4)-Mg(6) bond lengths are 3.10 Å. Both Mg(4)-Mg(7) bond lengths are 3.15 Å. In the fifth Mg site, Mg(5) is bonded in a 2-coordinate geometry to one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(6), one W(1), and one Si(1) atom. There is one shorter (3.06 Å) and one longer (3.14 Å) Mg(5)-Mg(6) bond length. The Mg(5)-W(1) bond length is 2.96 Å. The Mg(5)-Si(1) bond length is 2.98 Å. In the sixth Mg site, Mg(6) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(7), four equivalent Mg(5), and one Si(1) atom to form distorted MgMg11Si cuboctahedra that share corners with six equivalent Mg(6)Mg11Si cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Si(1)Mg10W2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(3)Mg8Si2W2 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra,  a faceface with one Si(1)Mg10W2 cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Mg8Si2W2 cuboctahedra, faces with three equivalent Mg(2)Mg12 cuboctahedra, and faces with three equivalent W(1)Mg10Si2 cuboctahedra. Both Mg(6)-Mg(7) bond lengths are 3.03 Å. The Mg(6)-Si(1) bond length is 3.06 Å. In the seventh Mg site, Mg(7) is bonded in a distorted single-bond geometry to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), and one W(1) atom. The Mg(7)-W(1) bond length is 3.00 Å. W(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Si(1) atoms to form WMg10Si2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent W(1)Mg10Si2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Si(1)Mg10W2 cuboctahedra, edges with four equivalent Mg(3)Mg8Si2W2 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Si(1)Mg10W2 cuboctahedra, faces with four equivalent Mg(3)Mg8Si2W2 cuboctahedra, and faces with six equivalent Mg(6)Mg11Si cuboctahedra. Both W(1)-Si(1) bond lengths are 3.03 Å. Si(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent W(1) atoms to form SiMg10W2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with six equivalent Si(1)Mg10W2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent W(1)Mg10Si2 cuboctahedra, edges with four equivalent Mg(6)Mg11Si cuboctahedra, edges with four equivalent Mg(3)Mg8Si2W2 cuboctahedra, faces with two equivalent Mg(6)Mg11Si cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent W(1)Mg10Si2 cuboctahedra, and faces with four equivalent Mg(3)Mg8Si2W2 cuboctahedra.