Mg2B4H15 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one H(10), one H(12), one H(2), one H(24), one H(28), one H(3), one H(4), and one H(9) atom. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to one H(13), one H(15), one H(16), one H(19), one H(25), one H(6), one H(7), and one H(8) atom. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one H(1), one H(17), one H(18), one H(20), one H(21), and one H(22) atom. In the fourth Mg site, Mg(4) is bonded in a 8-coordinate geometry to one H(11), one H(14), one H(23), one H(26), one H(28), one H(29), one H(30), and one H(4) atom. There are eight inequivalent B sites. In the first B site, B(1) is bonded in a tetrahedral geometry to one H(13), one H(26), one H(29), and one H(7) atom. In the second B site, B(2) is bonded in a distorted trigonal non-coplanar geometry to one H(15), one H(17), and one H(19) atom. In the third B site, B(3) is bonded in a tetrahedral geometry to one H(1), one H(16), one H(20), and one H(8) atom. In the fourth B site, B(4) is bonded in a distorted trigonal non-coplanar geometry to one H(10), one H(2), and one H(22) atom. In the fifth B site, B(5) is bonded in a tetrahedral geometry to one H(18), one H(21), one H(3), and one H(9) atom. In the sixth B site, B(6) is bonded in a tetrahedral geometry to one H(12), one H(23), one H(27), and one H(4) atom. In the seventh B site, B(7) is bonded in a tetrahedral geometry to one H(11), one H(24), one H(28), and one H(5) atom. In the eighth B site, B(8) is bonded in a tetrahedral geometry to one H(14), one H(25), one H(30), and one H(6) atom. There are thirty inequivalent H sites. In the first H site, H(1) is bonded in an L-shaped geometry to one Mg(3) and one B(3) atom. In the second H site, H(2) is bonded in an L-shaped geometry to one Mg(1) and one B(4) atom. In the third H site, H(3) is bonded in a distorted L-shaped geometry to one Mg(1) and one B(5) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to one Mg(1), one Mg(4), and one B(6) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one B(7) atom. In the sixth H site, H(6) is bonded in an L-shaped geometry to one Mg(2) and one B(8) atom. In the seventh H site, H(7) is bonded in a distorted L-shaped geometry to one Mg(2) and one B(1) atom. In the eighth H site, H(8) is bonded in an L-shaped geometry to one Mg(2) and one B(3) atom. In the ninth H site, H(9) is bonded in an L-shaped geometry to one Mg(1) and one B(5) atom. In the tenth H site, H(10) is bonded in an L-shaped geometry to one Mg(1) and one B(4) atom. In the eleventh H site, H(11) is bonded in a water-like geometry to one Mg(4) and one B(7) atom. In the twelfth H site, H(12) is bonded in a water-like geometry to one Mg(1) and one B(6) atom. In the thirteenth H site, H(13) is bonded in an L-shaped geometry to one Mg(2) and one B(1) atom. In the fourteenth H site, H(14) is bonded in an L-shaped geometry to one Mg(4) and one B(8) atom. In the fifteenth H site, H(15) is bonded in a distorted single-bond geometry to one Mg(2) and one B(2) atom. In the sixteenth H site, H(16) is bonded in a distorted L-shaped geometry to one Mg(2) and one B(3) atom. In the seventeenth H site, H(17) is bonded in a distorted L-shaped geometry to one Mg(3) and one B(2) atom. In the eighteenth H site, H(18) is bonded in an L-shaped geometry to one Mg(3) and one B(5) atom. In the nineteenth H site, H(19) is bonded in an L-shaped geometry to one Mg(2) and one B(2) atom. In the twentieth H site, H(20) is bonded in an L-shaped geometry to one Mg(3) and one B(3) atom. In the twenty-first H site, H(21) is bonded in an L-shaped geometry to one Mg(3) and one B(5) atom. In the twenty-second H site, H(22) is bonded in an L-shaped geometry to one Mg(3) and one B(4) atom. In the twenty-third H site, H(23) is bonded in a water-like geometry to one Mg(4) and one B(6) atom. In the twenty-fourth H site, H(24) is bonded in a water-like geometry to one Mg(1) and one B(7) atom. In the twenty-fifth H site, H(25) is bonded in an L-shaped geometry to one Mg(2) and one B(8) atom. In the twenty-sixth H site, H(26) is bonded in an L-shaped geometry to one Mg(4) and one B(1) atom. In the twenty-seventh H site, H(27) is bonded in a single-bond geometry to one B(6) atom. In the twenty-eighth H site, H(28) is bonded in a distorted single-bond geometry to one Mg(1), one Mg(4), and one B(7) atom. In the twenty-ninth H site, H(29) is bonded in an L-shaped geometry to one Mg(4) and one B(1) atom. In the thirtieth H site, H(30) is bonded in an L-shaped geometry to one Mg(4) and one B(8) atom.
Mg2B4H15 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one H(10), one H(12), one H(2), one H(24), one H(28), one H(3), one H(4), and one H(9) atom. The Mg(1)-H(10) bond length is 2.00 Å. The Mg(1)-H(12) bond length is 1.95 Å. The Mg(1)-H(2) bond length is 2.03 Å. The Mg(1)-H(24) bond length is 1.96 Å. The Mg(1)-H(28) bond length is 2.19 Å. The Mg(1)-H(3) bond length is 2.12 Å. The Mg(1)-H(4) bond length is 2.20 Å. The Mg(1)-H(9) bond length is 2.06 Å. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to one H(13), one H(15), one H(16), one H(19), one H(25), one H(6), one H(7), and one H(8) atom. The Mg(2)-H(13) bond length is 2.11 Å. The Mg(2)-H(15) bond length is 2.18 Å. The Mg(2)-H(16) bond length is 2.11 Å. The Mg(2)-H(19) bond length is 2.02 Å. The Mg(2)-H(25) bond length is 2.09 Å. The Mg(2)-H(6) bond length is 2.07 Å. The Mg(2)-H(7) bond length is 2.09 Å. The Mg(2)-H(8) bond length is 2.12 Å. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one H(1), one H(17), one H(18), one H(20), one H(21), and one H(22) atom. The Mg(3)-H(1) bond length is 2.00 Å. The Mg(3)-H(17) bond length is 2.05 Å. The Mg(3)-H(18) bond length is 2.02 Å. The Mg(3)-H(20) bond length is 2.03 Å. The Mg(3)-H(21) bond length is 2.00 Å. The Mg(3)-H(22) bond length is 1.96 Å. In the fourth Mg site, Mg(4) is bonded in a 8-coordinate geometry to one H(11), one H(14), one H(23), one H(26), one H(28), one H(29), one H(30), and one H(4) atom. The Mg(4)-H(11) bond length is 1.95 Å. The Mg(4)-H(14) bond length is 2.06 Å. The Mg(4)-H(23) bond length is 1.96 Å. The Mg(4)-H(26) bond length is 2.03 Å. The Mg(4)-H(28) bond length is 2.21 Å. The Mg(4)-H(29) bond length is 2.06 Å. The Mg(4)-H(30) bond length is 2.07 Å. The Mg(4)-H(4) bond length is 2.16 Å. There are eight inequivalent B sites. In the first B site, B(1) is bonded in a tetrahedral geometry to one H(13), one H(26), one H(29), and one H(7) atom. The B(1)-H(13) bond length is 1.22 Å. The B(1)-H(26) bond length is 1.23 Å. The B(1)-H(29) bond length is 1.23 Å. The B(1)-H(7) bond length is 1.23 Å. In the second B site, B(2) is bonded in a distorted trigonal non-coplanar geometry to one H(15), one H(17), and one H(19) atom. The B(2)-H(15) bond length is 1.24 Å. The B(2)-H(17) bond length is 1.25 Å. The B(2)-H(19) bond length is 1.22 Å. In the third B site, B(3) is bonded in a tetrahedral geometry to one H(1), one H(16), one H(20), and one H(8) atom. The B(3)-H(1) bond length is 1.23 Å. The B(3)-H(16) bond length is 1.22 Å. The B(3)-H(20) bond length is 1.23 Å. The B(3)-H(8) bond length is 1.22 Å. In the fourth B site, B(4) is bonded in a distorted trigonal non-coplanar geometry to one H(10), one H(2), and one H(22) atom. The B(4)-H(10) bond length is 1.24 Å. The B(4)-H(2) bond length is 1.23 Å. The B(4)-H(22) bond length is 1.25 Å. In the fifth B site, B(5) is bonded in a tetrahedral geometry to one H(18), one H(21), one H(3), and one H(9) atom. The B(5)-H(18) bond length is 1.23 Å. The B(5)-H(21) bond length is 1.23 Å. The B(5)-H(3) bond length is 1.22 Å. The B(5)-H(9) bond length is 1.22 Å. In the sixth B site, B(6) is bonded in a tetrahedral geometry to one H(12), one H(23), one H(27), and one H(4) atom. The B(6)-H(12) bond length is 1.24 Å. The B(6)-H(23) bond length is 1.24 Å. The B(6)-H(27) bond length is 1.20 Å. The B(6)-H(4) bond length is 1.24 Å. In the seventh B site, B(7) is bonded in a tetrahedral geometry to one H(11), one H(24), one H(28), and one H(5) atom. The B(7)-H(11) bond length is 1.24 Å. The B(7)-H(24) bond length is 1.24 Å. The B(7)-H(28) bond length is 1.24 Å. The B(7)-H(5) bond length is 1.20 Å. In the eighth B site, B(8) is bonded in a tetrahedral geometry to one H(14), one H(25), one H(30), and one H(6) atom. The B(8)-H(14) bond length is 1.23 Å. The B(8)-H(25) bond length is 1.22 Å. The B(8)-H(30) bond length is 1.23 Å. The B(8)-H(6) bond length is 1.23 Å. There are thirty inequivalent H sites. In the first H site, H(1) is bonded in an L-shaped geometry to one Mg(3) and one B(3) atom. In the second H site, H(2) is bonded in an L-shaped geometry to one Mg(1) and one B(4) atom. In the third H site, H(3) is bonded in a distorted L-shaped geometry to one Mg(1) and one B(5) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to one Mg(1), one Mg(4), and one B(6) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one B(7) atom. In the sixth H site, H(6) is bonded in an L-shaped geometry to one Mg(2) and one B(8) atom. In the seventh H site, H(7) is bonded in a distorted L-shaped geometry to one Mg(2) and one B(1) atom. In the eighth H site, H(8) is bonded in an L-shaped geometry to one Mg(2) and one B(3) atom. In the ninth H site, H(9) is bonded in an L-shaped geometry to one Mg(1) and one B(5) atom. In the tenth H site, H(10) is bonded in an L-shaped geometry to one Mg(1) and one B(4) atom. In the eleventh H site, H(11) is bonded in a water-like geometry to one Mg(4) and one B(7) atom. In the twelfth H site, H(12) is bonded in a water-like geometry to one Mg(1) and one B(6) atom. In the thirteenth H site, H(13) is bonded in an L-shaped geometry to one Mg(2) and one B(1) atom. In the fourteenth H site, H(14) is bonded in an L-shaped geometry to one Mg(4) and one B(8) atom. In the fifteenth H site, H(15) is bonded in a distorted single-bond geometry to one Mg(2) and one B(2) atom. In the sixteenth H site, H(16) is bonded in a distorted L-shaped geometry to one Mg(2) and one B(3) atom. In the seventeenth H site, H(17) is bonded in a distorted L-shaped geometry to one Mg(3) and one B(2) atom. In the eighteenth H site, H(18) is bonded in an L-shaped geometry to one Mg(3) and one B(5) atom. In the nineteenth H site, H(19) is bonded in an L-shaped geometry to one Mg(2) and one B(2) atom. In the twentieth H site, H(20) is bonded in an L-shaped geometry to one Mg(3) and one B(3) atom. In the twenty-first H site, H(21) is bonded in an L-shaped geometry to one Mg(3) and one B(5) atom. In the twenty-second H site, H(22) is bonded in an L-shaped geometry to one Mg(3) and one B(4) atom. In the twenty-third H site, H(23) is bonded in a water-like geometry to one Mg(4) and one B(6) atom. In the twenty-fourth H site, H(24) is bonded in a water-like geometry to one Mg(1) and one B(7) atom. In the twenty-fifth H site, H(25) is bonded in an L-shaped geometry to one Mg(2) and one B(8) atom. In the twenty-sixth H site, H(26) is bonded in an L-shaped geometry to one Mg(4) and one B(1) atom. In the twenty-seventh H site, H(27) is bonded in a single-bond geometry to one B(6) atom. In the twenty-eighth H site, H(28) is bonded in a distorted single-bond geometry to one Mg(1), one Mg(4), and one B(7) atom. In the twenty-ninth H site, H(29) is bonded in an L-shaped geometry to one Mg(4) and one B(1) atom. In the thirtieth H site, H(30) is bonded in an L-shaped geometry to one Mg(4) and one B(8) atom.