Mg2Si3 is Magnesium tetraboride-like 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 two equivalent Si(3) and four equivalent Si(6) atoms. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to one Si(2), three equivalent Si(4), and four equivalent Si(5) atoms. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Si(1), one Si(2), one Si(3), and two equivalent Si(6) atoms. In the fourth Mg site, Mg(4) is bonded in a 7-coordinate geometry to one Si(3), one Si(4), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(5) atoms. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to one Mg(3), two equivalent Mg(4), one Si(2), one Si(6), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to one Mg(2), one Mg(3), two equivalent Mg(4), one Si(1), and two equivalent Si(4) atoms. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Mg(3), one Mg(4), two equivalent Mg(1), one Si(6), and two equivalent Si(1) atoms. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to one Mg(4), three equivalent Mg(2), one Si(5), and two equivalent Si(2) atoms. In the fifth Si site, Si(5) is bonded in a 8-coordinate geometry to two equivalent Mg(4), four equivalent Mg(2), one Si(4), and one Si(5) atom. In the sixth Si site, Si(6) is bonded in a 8-coordinate geometry to two equivalent Mg(3), four equivalent Mg(1), one Si(1), and one Si(3) atom.
Mg2Si3 is Magnesium tetraboride-like 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 two equivalent Si(3) and four equivalent Si(6) atoms. There is one shorter (2.95 Å) and one longer (2.96 Å) Mg(1)-Si(3) bond length. There are a spread of Mg(1)-Si(6) bond distances ranging from 2.73-3.15 Å. In the second Mg site, Mg(2) is bonded in a 7-coordinate geometry to one Si(2), three equivalent Si(4), and four equivalent Si(5) atoms. The Mg(2)-Si(2) bond length is 2.92 Å. There are a spread of Mg(2)-Si(4) bond distances ranging from 2.76-2.98 Å. There are a spread of Mg(2)-Si(5) bond distances ranging from 2.75-3.08 Å. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Si(1), one Si(2), one Si(3), and two equivalent Si(6) atoms. The Mg(3)-Si(1) bond length is 2.81 Å. The Mg(3)-Si(2) bond length is 2.74 Å. The Mg(3)-Si(3) bond length is 2.69 Å. There is one shorter (2.72 Å) and one longer (2.75 Å) Mg(3)-Si(6) bond length. In the fourth Mg site, Mg(4) is bonded in a 7-coordinate geometry to one Si(3), one Si(4), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(5) atoms. The Mg(4)-Si(3) bond length is 2.89 Å. The Mg(4)-Si(4) bond length is 3.00 Å. There is one shorter (2.81 Å) and one longer (2.94 Å) Mg(4)-Si(1) bond length. There is one shorter (2.83 Å) and one longer (3.15 Å) Mg(4)-Si(2) bond length. There is one shorter (2.73 Å) and one longer (2.87 Å) Mg(4)-Si(5) bond length. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to one Mg(3), two equivalent Mg(4), one Si(2), one Si(6), and two equivalent Si(3) atoms. The Si(1)-Si(2) bond length is 2.46 Å. The Si(1)-Si(6) bond length is 2.55 Å. There is one shorter (2.39 Å) and one longer (2.48 Å) Si(1)-Si(3) bond length. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to one Mg(2), one Mg(3), two equivalent Mg(4), one Si(1), and two equivalent Si(4) atoms. There is one shorter (2.43 Å) and one longer (2.44 Å) Si(2)-Si(4) bond length. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Mg(3), one Mg(4), two equivalent Mg(1), one Si(6), and two equivalent Si(1) atoms. The Si(3)-Si(6) bond length is 2.41 Å. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to one Mg(4), three equivalent Mg(2), one Si(5), and two equivalent Si(2) atoms. The Si(4)-Si(5) bond length is 2.43 Å. In the fifth Si site, Si(5) is bonded in a 8-coordinate geometry to two equivalent Mg(4), four equivalent Mg(2), one Si(4), and one Si(5) atom. The Si(5)-Si(5) bond length is 2.56 Å. In the sixth Si site, Si(6) is bonded in a 8-coordinate geometry to two equivalent Mg(3), four equivalent Mg(1), one Si(1), and one Si(3) atom.