Ba4NaCuO4(CO3)2 crystallizes in the tetragonal I-42m space group. Na(1) is bonded in an octahedral geometry to two equivalent O(2) and four equivalent O(3) atoms. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(2), four equivalent O(1), and four equivalent O(3) atoms. Cu(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(3) atoms. C(1) is bonded in a trigonal planar geometry to one O(2) and two equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one C(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Na(1), four equivalent Ba(1), and one C(1) atom. In the third O site, O(3) is bonded to one Na(1), four equivalent Ba(1), and one Cu(1) atom to form a mixture of distorted face, corner, and edge-sharing OBa4NaCu octahedra. The corner-sharing octahedral tilt angles range from 2-3°.
Ba4NaCuO4(CO3)2 crystallizes in the tetragonal I-42m space group. Na(1) is bonded in an octahedral geometry to two equivalent O(2) and four equivalent O(3) atoms. Both Na(1)-O(2) bond lengths are 2.34 Å. All Na(1)-O(3) bond lengths are 2.31 Å. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(2), four equivalent O(1), and four equivalent O(3) atoms. Both Ba(1)-O(2) bond lengths are 3.00 Å. There are two shorter (2.87 Å) and two longer (3.36 Å) Ba(1)-O(1) bond lengths. There are two shorter (2.76 Å) and two longer (2.82 Å) Ba(1)-O(3) bond lengths. Cu(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(3) atoms. All Cu(1)-O(3) bond lengths are 1.87 Å. C(1) is bonded in a trigonal planar geometry to one O(2) and two equivalent O(1) atoms. The C(1)-O(2) bond length is 1.31 Å. Both C(1)-O(1) bond lengths are 1.30 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one C(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Na(1), four equivalent Ba(1), and one C(1) atom. In the third O site, O(3) is bonded to one Na(1), four equivalent Ba(1), and one Cu(1) atom to form a mixture of distorted face, corner, and edge-sharing OBa4NaCu octahedra. The corner-sharing octahedral tilt angles range from 2-3°.