Ba3TiNb4O15 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the tetragonal P4bm 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(3), two equivalent O(5), and four equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded to four equivalent O(1) and eight equivalent O(2) atoms to form BaO12 cuboctahedra that share faces with two equivalent Ba(2)O12 cuboctahedra and faces with eight equivalent Nb(1)O6 octahedra. Ti(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form distorted TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-36°. Nb(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form NbO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with five equivalent Nb(1)O6 octahedra, and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 6-43°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Ba(2) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Ba(2) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(1), one Ti(1), and one Nb(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ba(1) and two equivalent Nb(1) atoms.
Ba3TiNb4O15 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the tetragonal P4bm 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(3), two equivalent O(5), and four equivalent O(4) atoms. The Ba(1)-O(3) bond length is 2.94 Å. There is one shorter (2.87 Å) and one longer (3.06 Å) Ba(1)-O(5) bond length. There are two shorter (2.77 Å) and two longer (2.98 Å) Ba(1)-O(4) bond lengths. In the second Ba site, Ba(2) is bonded to four equivalent O(1) and eight equivalent O(2) atoms to form BaO12 cuboctahedra that share faces with two equivalent Ba(2)O12 cuboctahedra and faces with eight equivalent Nb(1)O6 octahedra. All Ba(2)-O(1) bond lengths are 2.82 Å. There are four shorter (2.78 Å) and four longer (2.94 Å) Ba(2)-O(2) bond lengths. Ti(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form distorted TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-36°. There is one shorter (1.75 Å) and one longer (2.39 Å) Ti(1)-O(3) bond length. All Ti(1)-O(4) bond lengths are 1.98 Å. Nb(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form NbO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with five equivalent Nb(1)O6 octahedra, and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 6-43°. The Nb(1)-O(4) bond length is 1.93 Å. The Nb(1)-O(5) bond length is 2.03 Å. There is one shorter (1.88 Å) and one longer (2.26 Å) Nb(1)-O(1) bond length. There is one shorter (2.05 Å) and one longer (2.07 Å) Nb(1)-O(2) bond length. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Ba(2) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Ba(2) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(1), one Ti(1), and one Nb(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ba(1) and two equivalent Nb(1) atoms.