Ba2MgPrNbO6 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms. Mg(1) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(6) atom to form distorted MgO5 trigonal bipyramids that share edges with two equivalent Nb(1)O5 trigonal bipyramids. Pr(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(6) atom to form distorted NbO5 trigonal bipyramids that share edges with two equivalent Mg(1)O5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Ba(2), one Mg(1), one Pr(1), and one Nb(1) atom to form a mixture of distorted corner and edge-sharing OBa2PrMgNb square pyramids. In the second O site, O(2) is bonded to one Ba(1), one Ba(2), one Mg(1), one Pr(1), and one Nb(1) atom to form a mixture of distorted face, corner, and edge-sharing OBa2PrMgNb square pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), one Pr(1), and one Nb(1) atom. In the fourth O site, O(4) is bonded to one Ba(1), one Ba(2), one Mg(1), one Pr(1), and one Nb(1) atom to form a mixture of distorted face, corner, and edge-sharing OBa2PrMgNb trigonal bipyramids. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), one Mg(1), and one Pr(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Mg(1), one Pr(1), and one Nb(1) atom.
Ba2MgPrNbO6 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms. The Ba(1)-O(1) bond length is 2.94 Å. The Ba(1)-O(2) bond length is 2.90 Å. The Ba(1)-O(3) bond length is 2.93 Å. The Ba(1)-O(4) bond length is 2.79 Å. The Ba(1)-O(6) bond length is 3.06 Å. There is one shorter (2.79 Å) and one longer (3.20 Å) Ba(1)-O(5) bond length. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms. The Ba(2)-O(1) bond length is 2.71 Å. The Ba(2)-O(2) bond length is 2.81 Å. The Ba(2)-O(3) bond length is 2.67 Å. The Ba(2)-O(4) bond length is 2.75 Å. The Ba(2)-O(6) bond length is 2.72 Å. There is one shorter (2.84 Å) and one longer (3.04 Å) Ba(2)-O(5) bond length. Mg(1) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(6) atom to form distorted MgO5 trigonal bipyramids that share edges with two equivalent Nb(1)O5 trigonal bipyramids. The Mg(1)-O(1) bond length is 2.13 Å. The Mg(1)-O(2) bond length is 2.04 Å. The Mg(1)-O(4) bond length is 2.05 Å. The Mg(1)-O(5) bond length is 2.07 Å. The Mg(1)-O(6) bond length is 2.14 Å. Pr(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Pr(1)-O(1) bond length is 2.38 Å. The Pr(1)-O(2) bond length is 2.46 Å. The Pr(1)-O(3) bond length is 2.56 Å. The Pr(1)-O(4) bond length is 2.51 Å. The Pr(1)-O(5) bond length is 2.50 Å. The Pr(1)-O(6) bond length is 2.33 Å. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(6) atom to form distorted NbO5 trigonal bipyramids that share edges with two equivalent Mg(1)O5 trigonal bipyramids. The Nb(1)-O(1) bond length is 2.16 Å. The Nb(1)-O(2) bond length is 2.14 Å. The Nb(1)-O(3) bond length is 1.90 Å. The Nb(1)-O(4) bond length is 2.15 Å. The Nb(1)-O(6) bond length is 2.10 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Ba(2), one Mg(1), one Pr(1), and one Nb(1) atom to form a mixture of distorted corner and edge-sharing OBa2PrMgNb square pyramids. In the second O site, O(2) is bonded to one Ba(1), one Ba(2), one Mg(1), one Pr(1), and one Nb(1) atom to form a mixture of distorted face, corner, and edge-sharing OBa2PrMgNb square pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), one Pr(1), and one Nb(1) atom. In the fourth O site, O(4) is bonded to one Ba(1), one Ba(2), one Mg(1), one Pr(1), and one Nb(1) atom to form a mixture of distorted face, corner, and edge-sharing OBa2PrMgNb trigonal bipyramids. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), one Mg(1), and one Pr(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Mg(1), one Pr(1), and one Nb(1) atom.