MgSi is Magnesium tetraboride-like structured and crystallizes in the triclinic P-1 space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to one Si(1), one Si(2), one Si(6), and two equivalent Si(4) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(1), one Si(4), two equivalent Si(2), and three equivalent Si(5) atoms. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one Si(4), two equivalent Si(3), and three equivalent Si(6) atoms. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to one Si(2), one Si(3), one Si(4), one Si(5), and two equivalent Si(1) atoms. In the fifth Mg site, Mg(5) is bonded in a 6-coordinate geometry to one Si(1), one Si(4), one Si(5), and three equivalent Si(2) atoms. In the sixth Mg site, Mg(6) is bonded in a 6-coordinate geometry to one Si(1), two equivalent Si(6), and three equivalent Si(3) atoms. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to one Mg(1), one Mg(2), one Mg(5), one Mg(6), two equivalent Mg(4), one Si(3), and one Si(4) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(4), two equivalent Mg(2), three equivalent Mg(5), and two equivalent Si(5) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Mg(4), two equivalent Mg(3), three equivalent Mg(6), one Si(1), and one Si(6) atom. In the fourth Si site, Si(4) is bonded in a 8-coordinate geometry to one Mg(2), one Mg(3), one Mg(4), one Mg(5), two equivalent Mg(1), one Si(1), and one Si(6) atom. In the fifth Si site, Si(5) is bonded in a 7-coordinate geometry to one Mg(4), one Mg(5), three equivalent Mg(2), and two equivalent Si(2) atoms. In the sixth Si site, Si(6) is bonded in a 8-coordinate geometry to one Mg(1), two equivalent Mg(6), three equivalent Mg(3), one Si(3), and one Si(4) atom.
MgSi is Magnesium tetraboride-like structured and crystallizes in the triclinic P-1 space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to one Si(1), one Si(2), one Si(6), and two equivalent Si(4) atoms. The Mg(1)-Si(1) bond length is 2.99 Å. The Mg(1)-Si(2) bond length is 2.72 Å. The Mg(1)-Si(6) bond length is 2.79 Å. There is one shorter (2.81 Å) and one longer (3.04 Å) Mg(1)-Si(4) bond length. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(1), one Si(4), two equivalent Si(2), and three equivalent Si(5) atoms. The Mg(2)-Si(1) bond length is 2.93 Å. The Mg(2)-Si(4) bond length is 2.84 Å. There is one shorter (2.92 Å) and one longer (3.12 Å) Mg(2)-Si(2) bond length. There are a spread of Mg(2)-Si(5) bond distances ranging from 2.72-2.83 Å. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one Si(4), two equivalent Si(3), and three equivalent Si(6) atoms. The Mg(3)-Si(4) bond length is 2.89 Å. There is one shorter (2.78 Å) and one longer (2.91 Å) Mg(3)-Si(3) bond length. There are a spread of Mg(3)-Si(6) bond distances ranging from 2.78-2.92 Å. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to one Si(2), one Si(3), one Si(4), one Si(5), and two equivalent Si(1) atoms. The Mg(4)-Si(2) bond length is 3.02 Å. The Mg(4)-Si(3) bond length is 2.79 Å. The Mg(4)-Si(4) bond length is 2.89 Å. The Mg(4)-Si(5) bond length is 2.72 Å. Both Mg(4)-Si(1) bond lengths are 2.76 Å. In the fifth Mg site, Mg(5) is bonded in a 6-coordinate geometry to one Si(1), one Si(4), one Si(5), and three equivalent Si(2) atoms. The Mg(5)-Si(1) bond length is 2.79 Å. The Mg(5)-Si(4) bond length is 2.79 Å. The Mg(5)-Si(5) bond length is 2.78 Å. There are a spread of Mg(5)-Si(2) bond distances ranging from 2.79-3.02 Å. In the sixth Mg site, Mg(6) is bonded in a 6-coordinate geometry to one Si(1), two equivalent Si(6), and three equivalent Si(3) atoms. The Mg(6)-Si(1) bond length is 2.73 Å. There is one shorter (2.77 Å) and one longer (2.88 Å) Mg(6)-Si(6) bond length. There are a spread of Mg(6)-Si(3) bond distances ranging from 2.80-3.02 Å. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to one Mg(1), one Mg(2), one Mg(5), one Mg(6), two equivalent Mg(4), one Si(3), and one Si(4) atom. The Si(1)-Si(3) bond length is 2.43 Å. The Si(1)-Si(4) bond length is 2.52 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(4), two equivalent Mg(2), three equivalent Mg(5), and two equivalent Si(5) atoms. There is one shorter (2.46 Å) and one longer (2.52 Å) Si(2)-Si(5) bond length. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Mg(4), two equivalent Mg(3), three equivalent Mg(6), one Si(1), and one Si(6) atom. The Si(3)-Si(6) bond length is 2.62 Å. In the fourth Si site, Si(4) is bonded in a 8-coordinate geometry to one Mg(2), one Mg(3), one Mg(4), one Mg(5), two equivalent Mg(1), one Si(1), and one Si(6) atom. The Si(4)-Si(6) bond length is 2.43 Å. In the fifth Si site, Si(5) is bonded in a 7-coordinate geometry to one Mg(4), one Mg(5), three equivalent Mg(2), and two equivalent Si(2) atoms. In the sixth Si site, Si(6) is bonded in a 8-coordinate geometry to one Mg(1), two equivalent Mg(6), three equivalent Mg(3), one Si(3), and one Si(4) atom.