MgSi is Magnesium tetraboride-like structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to one Si(3), two equivalent Si(2), and three equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to two equivalent Si(3) and three equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one Si(2), one Si(3), and four equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to three equivalent Mg(1), four equivalent Mg(3), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(3), two equivalent Mg(1), three equivalent Mg(2), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(2), one Si(3), and two equivalent Si(2) atoms.
MgSi is Magnesium tetraboride-like structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to one Si(3), two equivalent Si(2), and three equivalent Si(1) atoms. The Mg(1)-Si(3) bond length is 2.82 Å. Both Mg(1)-Si(2) bond lengths are 2.85 Å. There is one shorter (2.65 Å) and two longer (2.77 Å) Mg(1)-Si(1) bond lengths. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to two equivalent Si(3) and three equivalent Si(2) atoms. Both Mg(2)-Si(3) bond lengths are 2.93 Å. There is one shorter (2.70 Å) and two longer (2.90 Å) Mg(2)-Si(2) bond lengths. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one Si(2), one Si(3), and four equivalent Si(1) atoms. The Mg(3)-Si(2) bond length is 2.92 Å. The Mg(3)-Si(3) bond length is 3.12 Å. There are two shorter (2.82 Å) and two longer (2.87 Å) Mg(3)-Si(1) bond lengths. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to three equivalent Mg(1), four equivalent Mg(3), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.31 Å. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(3), two equivalent Mg(1), three equivalent Mg(2), and two equivalent Si(3) atoms. Both Si(2)-Si(3) bond lengths are 2.45 Å. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(2), one Si(3), and two equivalent Si(2) atoms. The Si(3)-Si(3) bond length is 2.48 Å.