Mg2B2O5 crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form distorted edge-sharing MgO6 octahedra. In the second Mg site, Mg(2) is bonded to one O(1), two equivalent O(5), and three equivalent O(2) atoms to form edge-sharing MgO6 octahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(2), two equivalent Mg(1), and one B(2) atom to form a mixture of distorted corner and edge-sharing OMg3B trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Mg(2) and one B(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one B(1), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one B(1) atom. In the fifth O site, O(5) is bonded to one Mg(1), two equivalent Mg(2), and one B(1) atom to form a mixture of distorted corner and edge-sharing OMg3B tetrahedra.
Mg2B2O5 crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form distorted edge-sharing MgO6 octahedra. The Mg(1)-O(3) bond length is 2.12 Å. The Mg(1)-O(5) bond length is 2.06 Å. Both Mg(1)-O(1) bond lengths are 2.21 Å. There is one shorter (1.97 Å) and one longer (2.02 Å) Mg(1)-O(4) bond length. In the second Mg site, Mg(2) is bonded to one O(1), two equivalent O(5), and three equivalent O(2) atoms to form edge-sharing MgO6 octahedra. The Mg(2)-O(1) bond length is 2.02 Å. There is one shorter (2.09 Å) and one longer (2.11 Å) Mg(2)-O(5) bond length. There are a spread of Mg(2)-O(2) bond distances ranging from 2.07-2.14 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. The B(1)-O(3) bond length is 1.42 Å. The B(1)-O(4) bond length is 1.34 Å. The B(1)-O(5) bond length is 1.37 Å. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The B(2)-O(1) bond length is 1.35 Å. The B(2)-O(2) bond length is 1.36 Å. The B(2)-O(3) bond length is 1.43 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(2), two equivalent Mg(1), and one B(2) atom to form a mixture of distorted corner and edge-sharing OMg3B trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Mg(2) and one B(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one B(1), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one B(1) atom. In the fifth O site, O(5) is bonded to one Mg(1), two equivalent Mg(2), and one B(1) atom to form a mixture of distorted corner and edge-sharing OMg3B tetrahedra.