MgSi2 is Magnesium tetraboride-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to two equivalent Mg(2), one Si(2), one Si(4), three equivalent Si(1), and four equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to two equivalent Mg(1), two equivalent Si(2), and four equivalent Si(4) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to three equivalent Mg(1), one Si(2), and three equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 6-coordinate geometry to one Mg(1), two equivalent Mg(2), one Si(1), and two equivalent Si(4) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to four equivalent Mg(1), one Si(3), and three equivalent Si(1) atoms. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to one Mg(1), four equivalent Mg(2), one Si(4), and two equivalent Si(2) atoms.
MgSi2 is Magnesium tetraboride-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to two equivalent Mg(2), one Si(2), one Si(4), three equivalent Si(1), and four equivalent Si(3) atoms. Both Mg(1)-Mg(2) bond lengths are 3.20 Å. The Mg(1)-Si(2) bond length is 2.91 Å. The Mg(1)-Si(4) bond length is 3.30 Å. There are two shorter (2.92 Å) and one longer (2.99 Å) Mg(1)-Si(1) bond length. There are two shorter (2.99 Å) and two longer (3.13 Å) Mg(1)-Si(3) bond lengths. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to two equivalent Mg(1), two equivalent Si(2), and four equivalent Si(4) atoms. Both Mg(2)-Si(2) bond lengths are 2.87 Å. There are a spread of Mg(2)-Si(4) bond distances ranging from 2.80-2.97 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to three equivalent Mg(1), one Si(2), and three equivalent Si(3) atoms. The Si(1)-Si(2) bond length is 2.37 Å. There are two shorter (2.44 Å) and one longer (2.48 Å) Si(1)-Si(3) bond length. In the second Si site, Si(2) is bonded in a 6-coordinate geometry to one Mg(1), two equivalent Mg(2), one Si(1), and two equivalent Si(4) atoms. Both Si(2)-Si(4) bond lengths are 2.42 Å. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to four equivalent Mg(1), one Si(3), and three equivalent Si(1) atoms. The Si(3)-Si(3) bond length is 2.37 Å. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to one Mg(1), four equivalent Mg(2), one Si(4), and two equivalent Si(2) atoms. The Si(4)-Si(4) bond length is 2.47 Å.