(BaC2O4)4O2 crystallizes in the triclinic P-1 space group. The structure consists of one hydrogen peroxide molecule inside a BaC2O4 framework. In the BaC2O4 framework, there are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), two equivalent O(6), and two equivalent O(7) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(8) atoms. There are four inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(7) atom. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(5) atom. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(4) atom. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one O(6) and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(3) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(3) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one C(4) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one C(1) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one C(4) atom.
(BaC2O4)4O2 crystallizes in the triclinic P-1 space group. The structure consists of one hydrogen peroxide molecule inside a BaC2O4 framework. In the BaC2O4 framework, there are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), two equivalent O(6), and two equivalent O(7) atoms. The Ba(1)-O(2) bond length is 2.95 Å. The Ba(1)-O(3) bond length is 2.91 Å. The Ba(1)-O(4) bond length is 2.83 Å. The Ba(1)-O(5) bond length is 2.84 Å. There is one shorter (2.79 Å) and one longer (2.82 Å) Ba(1)-O(6) bond length. There is one shorter (2.78 Å) and one longer (2.81 Å) Ba(1)-O(7) bond length. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(8) atoms. The Ba(2)-O(2) bond length is 2.84 Å. The Ba(2)-O(3) bond length is 2.95 Å. The Ba(2)-O(4) bond length is 2.86 Å. The Ba(2)-O(5) bond length is 2.82 Å. The Ba(2)-O(6) bond length is 3.10 Å. The Ba(2)-O(7) bond length is 3.30 Å. There is one shorter (2.81 Å) and one longer (2.91 Å) Ba(2)-O(1) bond length. There is one shorter (2.76 Å) and one longer (2.91 Å) Ba(2)-O(8) bond length. There are four inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(7) atom. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(7) bond length is 1.28 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(5) atom. The C(2)-O(3) bond length is 1.27 Å. The C(2)-O(5) bond length is 1.27 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(4) atom. The C(3)-O(2) bond length is 1.27 Å. The C(3)-O(4) bond length is 1.27 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one O(6) and one O(8) atom. The C(4)-O(6) bond length is 1.28 Å. The C(4)-O(8) bond length is 1.26 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(3) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(3) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one C(4) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one C(1) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one C(4) atom.