Ba3Sr(HgO2)4 crystallizes in the trigonal P321 space group. There are five inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to six equivalent O(3) atoms. In the fourth Ba site, Ba(4) is bonded in a 6-coordinate geometry to six equivalent O(4) atoms. In the fifth Ba site, Ba(5) is bonded in a 6-coordinate geometry to six equivalent O(3) atoms. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to six equivalent O(4) atoms. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a linear geometry to one O(1) and one O(3) atom. In the second Hg site, Hg(2) is bonded in a linear geometry to one O(2) and one O(4) atom. There are four inequivalent O sites. In the first O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ba(5), two equivalent Ba(3), and one Hg(1) atom. In the second O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(4), one Sr(1), and one Hg(2) atom. In the third O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Sr(2), and one Hg(1) atom. In the fourth O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Sr(2), and one Hg(2) atom.
Ba3Sr(HgO2)4 crystallizes in the trigonal P321 space group. There are five inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Ba(1)-O(1) bond lengths are 2.70 Å. All Ba(1)-O(2) bond lengths are 2.80 Å. In the second Ba site, Ba(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Ba(2)-O(1) bond lengths are 2.80 Å. All Ba(2)-O(2) bond lengths are 2.71 Å. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to six equivalent O(3) atoms. There are three shorter (2.67 Å) and three longer (2.79 Å) Ba(3)-O(3) bond lengths. In the fourth Ba site, Ba(4) is bonded in a 6-coordinate geometry to six equivalent O(4) atoms. There are three shorter (2.71 Å) and three longer (2.80 Å) Ba(4)-O(4) bond lengths. In the fifth Ba site, Ba(5) is bonded in a 6-coordinate geometry to six equivalent O(3) atoms. All Ba(5)-O(3) bond lengths are 2.68 Å. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to six equivalent O(4) atoms. All Sr(1)-O(4) bond lengths are 2.56 Å. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Sr(2)-O(1) bond lengths are 2.56 Å. All Sr(2)-O(2) bond lengths are 2.56 Å. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a linear geometry to one O(1) and one O(3) atom. The Hg(1)-O(1) bond length is 2.02 Å. The Hg(1)-O(3) bond length is 2.02 Å. In the second Hg site, Hg(2) is bonded in a linear geometry to one O(2) and one O(4) atom. The Hg(2)-O(2) bond length is 2.02 Å. The Hg(2)-O(4) bond length is 2.02 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ba(5), two equivalent Ba(3), and one Hg(1) atom. In the second O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(4), one Sr(1), and one Hg(2) atom. In the third O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Sr(2), and one Hg(1) atom. In the fourth O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Sr(2), and one Hg(2) atom.