MgSi crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 13-coordinate geometry to one Mg(1), one Mg(2), two equivalent Mg(3), one Si(2), four equivalent Si(1), and four equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Mg(1), one Si(3), two equivalent Si(1), and three equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), one Si(1), and three equivalent Si(2) atoms to form distorted edge-sharing MgMg2Si4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Mg(3), two equivalent Mg(2), four equivalent Mg(1), and three equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(1), three equivalent Mg(2), three equivalent Mg(3), and one Si(2) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(2), four equivalent Mg(1), one Si(3), and three equivalent Si(1) atoms.
MgSi crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 13-coordinate geometry to one Mg(1), one Mg(2), two equivalent Mg(3), one Si(2), four equivalent Si(1), and four equivalent Si(3) atoms. The Mg(1)-Mg(1) bond length is 3.16 Å. The Mg(1)-Mg(2) bond length is 3.31 Å. There is one shorter (3.18 Å) and one longer (3.25 Å) Mg(1)-Mg(3) bond length. The Mg(1)-Si(2) bond length is 2.82 Å. There are a spread of Mg(1)-Si(1) bond distances ranging from 2.96-3.15 Å. There are a spread of Mg(1)-Si(3) bond distances ranging from 2.88-3.21 Å. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Mg(1), one Si(3), two equivalent Si(1), and three equivalent Si(2) atoms. The Mg(2)-Si(3) bond length is 2.76 Å. There is one shorter (2.94 Å) and one longer (3.01 Å) Mg(2)-Si(1) bond length. There is one shorter (2.77 Å) and two longer (2.92 Å) Mg(2)-Si(2) bond lengths. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), one Si(1), and three equivalent Si(2) atoms to form distorted edge-sharing MgMg2Si4 tetrahedra. The Mg(3)-Si(1) bond length is 2.75 Å. There are a spread of Mg(3)-Si(2) bond distances ranging from 2.68-2.75 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Mg(3), two equivalent Mg(2), four equivalent Mg(1), and three equivalent Si(3) atoms. There are a spread of Si(1)-Si(3) bond distances ranging from 2.43-2.69 Å. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(1), three equivalent Mg(2), three equivalent Mg(3), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.43 Å. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(2), four equivalent Mg(1), one Si(3), and three equivalent Si(1) atoms. The Si(3)-Si(3) bond length is 2.53 Å.