Ba3TiO5 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(2) and eight equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to two equivalent O(2) and six equivalent O(1) atoms. Ti(1) is bonded in a tetrahedral geometry to four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Ba(1), three equivalent Ba(2), and one Ti(1) atom. In the second O site, O(2) is bonded to two equivalent Ba(1) and four equivalent Ba(2) atoms to form corner-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-32°.
Ba3TiO5 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(2) and eight equivalent O(1) atoms. Both Ba(1)-O(2) bond lengths are 2.99 Å. All Ba(1)-O(1) bond lengths are 3.05 Å. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to two equivalent O(2) and six equivalent O(1) atoms. Both Ba(2)-O(2) bond lengths are 2.70 Å. There are two shorter (2.67 Å) and four longer (3.01 Å) Ba(2)-O(1) bond lengths. Ti(1) is bonded in a tetrahedral geometry to four equivalent O(1) atoms. All Ti(1)-O(1) bond lengths are 1.82 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Ba(1), three equivalent Ba(2), and one Ti(1) atom. In the second O site, O(2) is bonded to two equivalent Ba(1) and four equivalent Ba(2) atoms to form corner-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-32°.