Mg2Si3 crystallizes in the triclinic P1 space group. There are eight inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one Si(1), two equivalent Si(3), two equivalent Si(6), and three equivalent Si(11) atoms. In the second Mg site, Mg(2) is bonded in a 9-coordinate geometry to one Si(4), one Si(7), two equivalent Si(2), two equivalent Si(5), and three equivalent Si(12) atoms. In the third Mg site, Mg(3) is bonded in a 9-coordinate geometry to two equivalent Si(1), two equivalent Si(11), two equivalent Si(4), and three equivalent Si(3) atoms. In the fourth Mg site, Mg(4) is bonded in a 9-coordinate geometry to two equivalent Si(1), two equivalent Si(12), two equivalent Si(4), and three equivalent Si(2) atoms. In the fifth Mg site, Mg(5) is bonded in a 7-coordinate geometry to one Si(7), one Si(9), two equivalent Si(12), and three equivalent Si(5) atoms. In the sixth Mg site, Mg(6) is bonded in a 8-coordinate geometry to one Si(8), two equivalent Si(10), two equivalent Si(11), and three equivalent Si(6) atoms. In the seventh Mg site, Mg(7) is bonded in a 8-coordinate geometry to one Si(10), one Si(5), one Si(7), two equivalent Si(8), and three equivalent Si(9) atoms. In the eighth Mg site, Mg(8) is bonded in a 8-coordinate geometry to one Si(9), two equivalent Si(6), two equivalent Si(8), and three equivalent Si(10) atoms. There are twelve inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), one Si(2), one Si(4), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(4), one Si(1), one Si(12), and two equivalent Si(4) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(1), three equivalent Mg(3), one Si(11), one Si(4), and two equivalent Si(1) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), one Si(1), one Si(3), and two equivalent Si(2) atoms. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to one Mg(7), two equivalent Mg(2), three equivalent Mg(5), one Si(12), and two equivalent Si(7) atoms. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Mg(8), three equivalent Mg(6), one Si(10), and one Si(11) atom. In the seventh Si site, Si(7) is bonded in a 8-coordinate geometry to one Mg(2), one Mg(5), one Mg(7), one Si(8), two equivalent Si(5), and two equivalent Si(9) atoms. In the eighth Si site, Si(8) is bonded in a 10-coordinate geometry to one Mg(6), two equivalent Mg(7), two equivalent Mg(8), one Si(7), two equivalent Si(10), and two equivalent Si(9) atoms. In the ninth Si site, Si(9) is bonded in a 9-coordinate geometry to one Mg(5), one Mg(8), three equivalent Mg(7), two equivalent Si(7), and two equivalent Si(8) atoms. In the tenth Si site, Si(10) is bonded in a 9-coordinate geometry to one Mg(7), two equivalent Mg(6), three equivalent Mg(8), one Si(6), and two equivalent Si(8) atoms. In the eleventh Si site, Si(11) is bonded in a 9-coordinate geometry to two equivalent Mg(3), two equivalent Mg(6), three equivalent Mg(1), one Si(3), and one Si(6) atom. In the twelfth Si site, Si(12) is bonded in a 9-coordinate geometry to two equivalent Mg(4), two equivalent Mg(5), three equivalent Mg(2), one Si(2), and one Si(5) atom.
Mg2Si3 crystallizes in the triclinic P1 space group. There are eight inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one Si(1), two equivalent Si(3), two equivalent Si(6), and three equivalent Si(11) atoms. The Mg(1)-Si(1) bond length is 3.06 Å. There is one shorter (2.89 Å) and one longer (2.91 Å) Mg(1)-Si(3) bond length. There is one shorter (2.83 Å) and one longer (2.84 Å) Mg(1)-Si(6) bond length. There are a spread of Mg(1)-Si(11) bond distances ranging from 2.79-3.06 Å. In the second Mg site, Mg(2) is bonded in a 9-coordinate geometry to one Si(4), one Si(7), two equivalent Si(2), two equivalent Si(5), and three equivalent Si(12) atoms. The Mg(2)-Si(4) bond length is 2.97 Å. The Mg(2)-Si(7) bond length is 3.05 Å. Both Mg(2)-Si(2) bond lengths are 2.99 Å. There is one shorter (2.83 Å) and one longer (2.85 Å) Mg(2)-Si(5) bond length. There are a spread of Mg(2)-Si(12) bond distances ranging from 2.80-3.05 Å. In the third Mg site, Mg(3) is bonded in a 9-coordinate geometry to two equivalent Si(1), two equivalent Si(11), two equivalent Si(4), and three equivalent Si(3) atoms. There is one shorter (2.76 Å) and one longer (2.92 Å) Mg(3)-Si(1) bond length. There is one shorter (2.75 Å) and one longer (2.76 Å) Mg(3)-Si(11) bond length. There is one shorter (2.91 Å) and one longer (3.02 Å) Mg(3)-Si(4) bond length. There are a spread of Mg(3)-Si(3) bond distances ranging from 2.86-3.02 Å. In the fourth Mg site, Mg(4) is bonded in a 9-coordinate geometry to two equivalent Si(1), two equivalent Si(12), two equivalent Si(4), and three equivalent Si(2) atoms. There is one shorter (2.92 Å) and one longer (3.02 Å) Mg(4)-Si(1) bond length. There is one shorter (2.78 Å) and one longer (2.81 Å) Mg(4)-Si(12) bond length. There is one shorter (2.83 Å) and one longer (2.99 Å) Mg(4)-Si(4) bond length. There are a spread of Mg(4)-Si(2) bond distances ranging from 2.88-3.02 Å. In the fifth Mg site, Mg(5) is bonded in a 7-coordinate geometry to one Si(7), one Si(9), two equivalent Si(12), and three equivalent Si(5) atoms. The Mg(5)-Si(7) bond length is 3.08 Å. The Mg(5)-Si(9) bond length is 2.70 Å. There is one shorter (2.79 Å) and one longer (2.81 Å) Mg(5)-Si(12) bond length. There are a spread of Mg(5)-Si(5) bond distances ranging from 2.87-2.99 Å. In the sixth Mg site, Mg(6) is bonded in a 8-coordinate geometry to one Si(8), two equivalent Si(10), two equivalent Si(11), and three equivalent Si(6) atoms. The Mg(6)-Si(8) bond length is 3.10 Å. There is one shorter (2.87 Å) and one longer (2.93 Å) Mg(6)-Si(10) bond length. There is one shorter (2.85 Å) and one longer (2.88 Å) Mg(6)-Si(11) bond length. There are a spread of Mg(6)-Si(6) bond distances ranging from 2.77-3.09 Å. In the seventh Mg site, Mg(7) is bonded in a 8-coordinate geometry to one Si(10), one Si(5), one Si(7), two equivalent Si(8), and three equivalent Si(9) atoms. The Mg(7)-Si(10) bond length is 2.75 Å. The Mg(7)-Si(5) bond length is 2.77 Å. The Mg(7)-Si(7) bond length is 2.99 Å. There is one shorter (3.15 Å) and one longer (3.16 Å) Mg(7)-Si(8) bond length. There are a spread of Mg(7)-Si(9) bond distances ranging from 2.79-3.13 Å. In the eighth Mg site, Mg(8) is bonded in a 8-coordinate geometry to one Si(9), two equivalent Si(6), two equivalent Si(8), and three equivalent Si(10) atoms. The Mg(8)-Si(9) bond length is 2.73 Å. There is one shorter (2.81 Å) and one longer (2.82 Å) Mg(8)-Si(6) bond length. There is one shorter (3.08 Å) and one longer (3.12 Å) Mg(8)-Si(8) bond length. There are a spread of Mg(8)-Si(10) bond distances ranging from 2.87-3.05 Å. There are twelve inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), one Si(2), one Si(4), and two equivalent Si(3) atoms. The Si(1)-Si(2) bond length is 2.42 Å. The Si(1)-Si(4) bond length is 2.50 Å. There is one shorter (2.58 Å) and one longer (2.60 Å) Si(1)-Si(3) bond length. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(4), one Si(1), one Si(12), and two equivalent Si(4) atoms. The Si(2)-Si(12) bond length is 2.41 Å. Both Si(2)-Si(4) bond lengths are 2.52 Å. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(1), three equivalent Mg(3), one Si(11), one Si(4), and two equivalent Si(1) atoms. The Si(3)-Si(11) bond length is 2.49 Å. The Si(3)-Si(4) bond length is 2.44 Å. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), one Si(1), one Si(3), and two equivalent Si(2) atoms. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to one Mg(7), two equivalent Mg(2), three equivalent Mg(5), one Si(12), and two equivalent Si(7) atoms. The Si(5)-Si(12) bond length is 2.42 Å. There is one shorter (2.49 Å) and one longer (2.55 Å) Si(5)-Si(7) bond length. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Mg(8), three equivalent Mg(6), one Si(10), and one Si(11) atom. The Si(6)-Si(10) bond length is 2.38 Å. The Si(6)-Si(11) bond length is 2.41 Å. In the seventh Si site, Si(7) is bonded in a 8-coordinate geometry to one Mg(2), one Mg(5), one Mg(7), one Si(8), two equivalent Si(5), and two equivalent Si(9) atoms. The Si(7)-Si(8) bond length is 2.58 Å. There is one shorter (2.58 Å) and one longer (2.70 Å) Si(7)-Si(9) bond length. In the eighth Si site, Si(8) is bonded in a 10-coordinate geometry to one Mg(6), two equivalent Mg(7), two equivalent Mg(8), one Si(7), two equivalent Si(10), and two equivalent Si(9) atoms. There is one shorter (2.49 Å) and one longer (2.54 Å) Si(8)-Si(10) bond length. There is one shorter (2.59 Å) and one longer (2.67 Å) Si(8)-Si(9) bond length. In the ninth Si site, Si(9) is bonded in a 9-coordinate geometry to one Mg(5), one Mg(8), three equivalent Mg(7), two equivalent Si(7), and two equivalent Si(8) atoms. In the tenth Si site, Si(10) is bonded in a 9-coordinate geometry to one Mg(7), two equivalent Mg(6), three equivalent Mg(8), one Si(6), and two equivalent Si(8) atoms. In the eleventh Si site, Si(11) is bonded in a 9-coordinate geometry to two equivalent Mg(3), two equivalent Mg(6), three equivalent Mg(1), one Si(3), and one Si(6) atom. In the twelfth Si site, Si(12) is bonded in a 9-coordinate geometry to two equivalent Mg(4), two equivalent Mg(5), three equivalent Mg(2), one Si(2), and one Si(5) atom.