Mg4Si3 is beta Plutonium-derived structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to one Si(1), one Si(3), one Si(4), and two equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(1), one Si(3), two equivalent Si(2), and two equivalent Si(4) atoms. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Si(3), one Si(4), two equivalent Si(2), and three equivalent Si(1) atoms. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to two equivalent Si(2) and four equivalent Si(1) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(2), three equivalent Mg(3), four equivalent Mg(4), one Si(1), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 11-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), one Si(1), one Si(3), and one Si(4) atom. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Si(2), and two equivalent Si(4) atoms. In the fourth Si site, Si(4) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), four equivalent Mg(2), two equivalent Si(2), and two equivalent Si(3) atoms.
Mg4Si3 is beta Plutonium-derived structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to one Si(1), one Si(3), one Si(4), and two equivalent Si(2) atoms. The Mg(1)-Si(1) bond length is 2.79 Å. The Mg(1)-Si(3) bond length is 2.75 Å. The Mg(1)-Si(4) bond length is 2.70 Å. There is one shorter (2.65 Å) and one longer (2.68 Å) Mg(1)-Si(2) bond length. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(1), one Si(3), two equivalent Si(2), and two equivalent Si(4) atoms. The Mg(2)-Si(1) bond length is 2.87 Å. The Mg(2)-Si(3) bond length is 2.93 Å. There is one shorter (2.94 Å) and one longer (3.13 Å) Mg(2)-Si(2) bond length. There is one shorter (3.07 Å) and one longer (3.11 Å) Mg(2)-Si(4) bond length. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Si(3), one Si(4), two equivalent Si(2), and three equivalent Si(1) atoms. The Mg(3)-Si(3) bond length is 2.81 Å. The Mg(3)-Si(4) bond length is 2.86 Å. There is one shorter (3.05 Å) and one longer (3.25 Å) Mg(3)-Si(2) bond length. There are a spread of Mg(3)-Si(1) bond distances ranging from 2.76-3.25 Å. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to two equivalent Si(2) and four equivalent Si(1) atoms. Both Mg(4)-Si(2) bond lengths are 2.94 Å. There are a spread of Mg(4)-Si(1) bond distances ranging from 2.90-3.11 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(2), three equivalent Mg(3), four equivalent Mg(4), one Si(1), and one Si(2) atom. The Si(1)-Si(1) bond length is 2.83 Å. The Si(1)-Si(2) bond length is 2.72 Å. In the second Si site, Si(2) is bonded in a 11-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), one Si(1), one Si(3), and one Si(4) atom. The Si(2)-Si(3) bond length is 2.61 Å. The Si(2)-Si(4) bond length is 2.68 Å. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Si(2), and two equivalent Si(4) atoms. Both Si(3)-Si(4) bond lengths are 2.87 Å. In the fourth Si site, Si(4) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), four equivalent Mg(2), two equivalent Si(2), and two equivalent Si(3) atoms.