Mg4Si3 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 Mg(4), one Si(2), two equivalent Si(3), and three equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to two equivalent Mg(4), one Si(3), two equivalent Si(1), and three equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to two equivalent Mg(4), one Si(2), two equivalent Si(1), and two equivalent Si(3) atoms. In the fourth Mg site, Mg(4) is bonded in a 12-coordinate geometry to one Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Si(1), two equivalent Si(2), and three equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and three equivalent Mg(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(4), three equivalent Mg(2), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 10-coordinate geometry to one Mg(2), two equivalent Mg(1), two equivalent Mg(3), three equivalent Mg(4), and two equivalent Si(2) atoms.
Mg4Si3 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 Mg(4), one Si(2), two equivalent Si(3), and three equivalent Si(1) atoms. The Mg(1)-Mg(4) bond length is 2.98 Å. The Mg(1)-Si(2) bond length is 2.77 Å. There is one shorter (2.96 Å) and one longer (3.19 Å) Mg(1)-Si(3) bond length. There are a spread of Mg(1)-Si(1) bond distances ranging from 2.89-3.10 Å. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to two equivalent Mg(4), one Si(3), two equivalent Si(1), and three equivalent Si(2) atoms. There is one shorter (2.90 Å) and one longer (3.12 Å) Mg(2)-Mg(4) bond length. The Mg(2)-Si(3) bond length is 2.93 Å. There is one shorter (2.77 Å) and one longer (2.86 Å) Mg(2)-Si(1) bond length. There are a spread of Mg(2)-Si(2) bond distances ranging from 2.92-3.22 Å. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to two equivalent Mg(4), one Si(2), two equivalent Si(1), and two equivalent Si(3) atoms. There is one shorter (3.02 Å) and one longer (3.07 Å) Mg(3)-Mg(4) bond length. The Mg(3)-Si(2) bond length is 2.79 Å. Both Mg(3)-Si(1) bond lengths are 2.90 Å. There is one shorter (2.88 Å) and one longer (2.91 Å) Mg(3)-Si(3) bond length. In the fourth Mg site, Mg(4) is bonded in a 12-coordinate geometry to one Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Si(1), two equivalent Si(2), and three equivalent Si(3) atoms. There is one shorter (2.76 Å) and one longer (3.11 Å) Mg(4)-Si(1) bond length. There is one shorter (2.85 Å) and one longer (2.91 Å) Mg(4)-Si(2) bond length. There are a spread of Mg(4)-Si(3) bond distances ranging from 2.82-2.99 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and three equivalent Mg(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(4), three equivalent Mg(2), and two equivalent Si(3) atoms. There is one shorter (2.52 Å) and one longer (2.76 Å) Si(2)-Si(3) bond length. In the third Si site, Si(3) is bonded in a 10-coordinate geometry to one Mg(2), two equivalent Mg(1), two equivalent Mg(3), three equivalent Mg(4), and two equivalent Si(2) atoms.