Ba2MgCu(PO4)2 crystallizes in the triclinic P-1 space group. Ba(1) is bonded in a 8-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(4) atoms. Cu(1) is bonded in a linear geometry to two equivalent O(2) atoms. P(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Mg(1), and one P(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Cu(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one Ba(1), one Mg(1), and one P(1) atom.
Ba2MgCu(PO4)2 crystallizes in the triclinic P-1 space group. Ba(1) is bonded in a 8-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. The Ba(1)-O(4) bond length is 2.78 Å. There is one shorter (2.79 Å) and one longer (2.99 Å) Ba(1)-O(1) bond length. There is one shorter (2.70 Å) and one longer (3.00 Å) Ba(1)-O(2) bond length. There are a spread of Ba(1)-O(3) bond distances ranging from 2.84-3.34 Å. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Mg(1)-O(1) bond lengths are 2.10 Å. Both Mg(1)-O(4) bond lengths are 2.10 Å. Cu(1) is bonded in a linear geometry to two equivalent O(2) atoms. Both Cu(1)-O(2) bond lengths are 2.17 Å. P(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The P(1)-O(1) bond length is 1.58 Å. The P(1)-O(2) bond length is 1.57 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.57 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Mg(1), and one P(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Cu(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one Ba(1), one Mg(1), and one P(1) atom.