Na2Ba3Ti3Nb2O15 is (Cubic) Perovskite-derived structured and crystallizes in the orthorhombic Cmmm space group. Na(1) is bonded to one O(5), three equivalent O(6), four equivalent O(2), and four equivalent O(3) atoms to form NaO12 cuboctahedra that share  a cornercorner with one Ba(2)O12 cuboctahedra, corners with five equivalent Ba(1)O12 cuboctahedra, corners with six equivalent Na(1)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Na(1)O12 cuboctahedra, faces with two equivalent Ti(2)O6 octahedra, and faces with six equivalent Nb(1)O6 octahedra. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(4), one O(6), two equivalent O(5), four equivalent O(1), and four equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with four equivalent Ba(2)O12 cuboctahedra, corners with five equivalent Na(1)O12 cuboctahedra, faces with two equivalent Na(1)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ti(1)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, and faces with four equivalent Ti(2)O6 octahedra. In the second Ba site, Ba(2) is bonded to two equivalent O(4), two equivalent O(5), and eight equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with two equivalent Na(1)O12 cuboctahedra, corners with two equivalent Ba(2)O12 cuboctahedra, corners with eight equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ti(1)O6 octahedra, and faces with four equivalent Ti(2)O6 octahedra. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with four equivalent Ti(2)O6 octahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with four equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ti site, Ti(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, faces with two equivalent Na(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are six inequivalent O sites. In the first O site, O(6) is bonded in a distorted linear geometry to three equivalent Na(1), one Ba(1), and two equivalent Nb(1) atoms. In the second O site, O(1) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Ti(1), and one Ti(2) atom. In the third O site, O(2) is bonded in a distorted linear geometry to two equivalent Na(1), two equivalent Ba(1), one Ti(2), and one Nb(1) atom. In the fourth O site, O(3) is bonded in a distorted linear geometry to four equivalent Na(1) and two equivalent Nb(1) atoms. In the fifth O site, O(4) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ti(1) atoms. In the sixth O site, O(5) is bonded in a distorted linear geometry to one Na(1), one Ba(2), two equivalent Ba(1), and two equivalent Ti(2) atoms.
Na2Ba3Ti3Nb2O15 is (Cubic) Perovskite-derived structured and crystallizes in the orthorhombic Cmmm space group. Na(1) is bonded to one O(5), three equivalent O(6), four equivalent O(2), and four equivalent O(3) atoms to form NaO12 cuboctahedra that share  a cornercorner with one Ba(2)O12 cuboctahedra, corners with five equivalent Ba(1)O12 cuboctahedra, corners with six equivalent Na(1)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Na(1)O12 cuboctahedra, faces with two equivalent Ti(2)O6 octahedra, and faces with six equivalent Nb(1)O6 octahedra. The Na(1)-O(5) bond length is 2.79 Å. There are two shorter (2.84 Å) and one longer (2.87 Å) Na(1)-O(6) bond length. All Na(1)-O(2) bond lengths are 2.83 Å. All Na(1)-O(3) bond lengths are 2.87 Å. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(4), one O(6), two equivalent O(5), four equivalent O(1), and four equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with four equivalent Ba(2)O12 cuboctahedra, corners with five equivalent Na(1)O12 cuboctahedra, faces with two equivalent Na(1)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ti(1)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, and faces with four equivalent Ti(2)O6 octahedra. The Ba(1)-O(4) bond length is 2.82 Å. The Ba(1)-O(6) bond length is 2.89 Å. Both Ba(1)-O(5) bond lengths are 2.84 Å. All Ba(1)-O(1) bond lengths are 2.83 Å. All Ba(1)-O(2) bond lengths are 2.86 Å. In the second Ba site, Ba(2) is bonded to two equivalent O(4), two equivalent O(5), and eight equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with two equivalent Na(1)O12 cuboctahedra, corners with two equivalent Ba(2)O12 cuboctahedra, corners with eight equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ti(1)O6 octahedra, and faces with four equivalent Ti(2)O6 octahedra. Both Ba(2)-O(4) bond lengths are 2.84 Å. Both Ba(2)-O(5) bond lengths are 2.87 Å. All Ba(2)-O(1) bond lengths are 2.85 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with four equivalent Ti(2)O6 octahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with four equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Ti(1)-O(4) bond lengths are 2.01 Å. All Ti(1)-O(1) bond lengths are 2.01 Å. In the second Ti site, Ti(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, faces with two equivalent Na(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. Both Ti(2)-O(1) bond lengths are 2.03 Å. Both Ti(2)-O(2) bond lengths are 1.99 Å. Both Ti(2)-O(5) bond lengths are 2.01 Å. Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. Both Nb(1)-O(2) bond lengths are 2.02 Å. Both Nb(1)-O(3) bond lengths are 2.00 Å. Both Nb(1)-O(6) bond lengths are 2.01 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded in a distorted linear geometry to three equivalent Na(1), one Ba(1), and two equivalent Nb(1) atoms. In the second O site, O(1) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Ti(1), and one Ti(2) atom. In the third O site, O(2) is bonded in a distorted linear geometry to two equivalent Na(1), two equivalent Ba(1), one Ti(2), and one Nb(1) atom. In the fourth O site, O(3) is bonded in a distorted linear geometry to four equivalent Na(1) and two equivalent Nb(1) atoms. In the fifth O site, O(4) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ti(1) atoms. In the sixth O site, O(5) is bonded in a distorted linear geometry to one Na(1), one Ba(2), two equivalent Ba(1), and two equivalent Ti(2) atoms.