Na2SrLa2Ti5O15 crystallizes in the monoclinic C2 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 12-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(16), one O(3), one O(4), one O(7), two equivalent O(12), and two equivalent O(5) atoms. In the second Na site, Na(2) is bonded in a 9-coordinate geometry to one O(10), one O(11), one O(14), one O(3), one O(8), two equivalent O(6), and two equivalent O(9) atoms. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to two equivalent O(1), two equivalent O(13), two equivalent O(15), two equivalent O(16), two equivalent O(2), and two equivalent O(4) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(2)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Ti(3)O6 octahedra. In the second Sr site, Sr(2) is bonded to two equivalent O(1), two equivalent O(13), two equivalent O(15), two equivalent O(16), two equivalent O(2), and two equivalent O(4) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(2)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Ti(3)O6 octahedra. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 12-coordinate geometry to one O(11), one O(14), one O(3), one O(7), two equivalent O(10), two equivalent O(6), two equivalent O(8), and two equivalent O(9) atoms. In the second La site, La(2) is bonded in a 12-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(16), one O(3), one O(4), one O(7), two equivalent O(12), and two equivalent O(5) atoms. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(11), one O(14), one O(3), one O(5), one O(7), and one O(8) atom to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 11-18°. In the second Ti site, Ti(2) is bonded to one O(1), one O(12), one O(13), one O(16), one O(2), and one O(4) atom to form TiO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(4)O6 octahedra, corners with four equivalent Ti(3)O6 octahedra, faces with two equivalent Sr(1)O12 cuboctahedra, and faces with two equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 11-15°. In the third Ti site, Ti(3) is bonded to one O(1), one O(13), one O(15), one O(16), one O(4), and one O(5) atom to form TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra, corners with four equivalent Ti(2)O6 octahedra, faces with two equivalent Sr(1)O12 cuboctahedra, and faces with two equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-15°. In the fourth Ti site, Ti(4) is bonded to one O(11), one O(12), one O(14), one O(3), one O(7), and one O(9) atom to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 11-18°. In the fifth Ti site, Ti(5) is bonded to one O(8), one O(9), two equivalent O(10), and two equivalent O(6) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 14-20°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Na(1), one Sr(1), one Sr(2), one La(2), one Ti(2), and one Ti(3) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), one La(1), one La(2), one Ti(1), and one Ti(4) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Na(1), one Sr(1), one Sr(2), one La(2), one Ti(2), and one Ti(3) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Na(1), two equivalent La(2), one Ti(1), and one Ti(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Na(2), two equivalent La(1), and two equivalent Ti(5) atoms. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Na(1), one La(1), one La(2), one Ti(1), and one Ti(4) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Na(2), two equivalent La(1), one Ti(1), and one Ti(5) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Na(2), two equivalent La(1), one Ti(4), and one Ti(5) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Na(2), two equivalent La(1), and two equivalent Ti(5) atoms. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), one La(1), one La(2), one Ti(1), and one Ti(4) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to two equivalent Na(1), two equivalent La(2), one Ti(2), and one Ti(4) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Na(1), one Sr(1), one Sr(2), one La(2), one Ti(2), and one Ti(3) atom. In the fourteenth O site, O(14) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one La(1), one La(2), one Ti(1), and one Ti(4) atom. In the fifteenth O site, O(15) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Ti(3) atoms. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to one Na(1), one Sr(1), one Sr(2), one La(2), one Ti(2), and one Ti(3) atom.
Na2SrLa2Ti5O15 crystallizes in the monoclinic C2 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 12-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(16), one O(3), one O(4), one O(7), two equivalent O(12), and two equivalent O(5) atoms. The Na(1)-O(1) bond length is 2.78 Å. The Na(1)-O(11) bond length is 2.76 Å. The Na(1)-O(13) bond length is 2.78 Å. The Na(1)-O(14) bond length is 3.04 Å. The Na(1)-O(16) bond length is 2.56 Å. The Na(1)-O(3) bond length is 2.80 Å. The Na(1)-O(4) bond length is 2.93 Å. The Na(1)-O(7) bond length is 2.57 Å. There is one shorter (2.53 Å) and one longer (3.00 Å) Na(1)-O(12) bond length. There is one shorter (2.77 Å) and one longer (2.79 Å) Na(1)-O(5) bond length. In the second Na site, Na(2) is bonded in a 9-coordinate geometry to one O(10), one O(11), one O(14), one O(3), one O(8), two equivalent O(6), and two equivalent O(9) atoms. The Na(2)-O(10) bond length is 2.52 Å. The Na(2)-O(11) bond length is 2.81 Å. The Na(2)-O(14) bond length is 2.51 Å. The Na(2)-O(3) bond length is 2.75 Å. The Na(2)-O(8) bond length is 2.50 Å. There is one shorter (2.76 Å) and one longer (2.80 Å) Na(2)-O(6) bond length. There is one shorter (2.76 Å) and one longer (2.79 Å) Na(2)-O(9) bond length. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to two equivalent O(1), two equivalent O(13), two equivalent O(15), two equivalent O(16), two equivalent O(2), and two equivalent O(4) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(2)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Ti(3)O6 octahedra. Both Sr(1)-O(1) bond lengths are 2.76 Å. Both Sr(1)-O(13) bond lengths are 2.76 Å. There is one shorter (2.59 Å) and one longer (2.94 Å) Sr(1)-O(15) bond length. Both Sr(1)-O(16) bond lengths are 2.97 Å. Both Sr(1)-O(2) bond lengths are 2.77 Å. Both Sr(1)-O(4) bond lengths are 2.61 Å. In the second Sr site, Sr(2) is bonded to two equivalent O(1), two equivalent O(13), two equivalent O(15), two equivalent O(16), two equivalent O(2), and two equivalent O(4) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(2)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Ti(3)O6 octahedra. Both Sr(2)-O(1) bond lengths are 2.60 Å. Both Sr(2)-O(13) bond lengths are 3.05 Å. Both Sr(2)-O(15) bond lengths are 2.77 Å. Both Sr(2)-O(16) bond lengths are 2.83 Å. There is one shorter (2.58 Å) and one longer (2.95 Å) Sr(2)-O(2) bond length. Both Sr(2)-O(4) bond lengths are 2.82 Å. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 12-coordinate geometry to one O(11), one O(14), one O(3), one O(7), two equivalent O(10), two equivalent O(6), two equivalent O(8), and two equivalent O(9) atoms. The La(1)-O(11) bond length is 2.45 Å. The La(1)-O(14) bond length is 2.79 Å. The La(1)-O(3) bond length is 3.06 Å. The La(1)-O(7) bond length is 2.79 Å. There is one shorter (2.73 Å) and one longer (2.74 Å) La(1)-O(10) bond length. There is one shorter (2.44 Å) and one longer (3.12 Å) La(1)-O(6) bond length. There is one shorter (2.70 Å) and one longer (2.85 Å) La(1)-O(8) bond length. There is one shorter (2.50 Å) and one longer (3.03 Å) La(1)-O(9) bond length. In the second La site, La(2) is bonded in a 12-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(16), one O(3), one O(4), one O(7), two equivalent O(12), and two equivalent O(5) atoms. The La(2)-O(1) bond length is 2.94 Å. The La(2)-O(11) bond length is 3.05 Å. The La(2)-O(13) bond length is 2.51 Å. The La(2)-O(14) bond length is 2.74 Å. The La(2)-O(16) bond length is 2.75 Å. The La(2)-O(3) bond length is 2.47 Å. The La(2)-O(4) bond length is 2.74 Å. The La(2)-O(7) bond length is 2.76 Å. There is one shorter (2.71 Å) and one longer (2.83 Å) La(2)-O(12) bond length. There is one shorter (2.49 Å) and one longer (3.04 Å) La(2)-O(5) bond length. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(11), one O(14), one O(3), one O(5), one O(7), and one O(8) atom to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 11-18°. The Ti(1)-O(11) bond length is 1.99 Å. The Ti(1)-O(14) bond length is 1.93 Å. The Ti(1)-O(3) bond length is 2.04 Å. The Ti(1)-O(5) bond length is 1.97 Å. The Ti(1)-O(7) bond length is 1.95 Å. The Ti(1)-O(8) bond length is 1.93 Å. In the second Ti site, Ti(2) is bonded to one O(1), one O(12), one O(13), one O(16), one O(2), and one O(4) atom to form TiO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(4)O6 octahedra, corners with four equivalent Ti(3)O6 octahedra, faces with two equivalent Sr(1)O12 cuboctahedra, and faces with two equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 11-15°. The Ti(2)-O(1) bond length is 1.99 Å. The Ti(2)-O(12) bond length is 1.93 Å. The Ti(2)-O(13) bond length is 2.00 Å. The Ti(2)-O(16) bond length is 1.95 Å. The Ti(2)-O(2) bond length is 2.01 Å. The Ti(2)-O(4) bond length is 1.94 Å. In the third Ti site, Ti(3) is bonded to one O(1), one O(13), one O(15), one O(16), one O(4), and one O(5) atom to form TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra, corners with four equivalent Ti(2)O6 octahedra, faces with two equivalent Sr(1)O12 cuboctahedra, and faces with two equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-15°. The Ti(3)-O(1) bond length is 1.94 Å. The Ti(3)-O(13) bond length is 1.96 Å. The Ti(3)-O(15) bond length is 1.98 Å. The Ti(3)-O(16) bond length is 1.98 Å. The Ti(3)-O(4) bond length is 1.98 Å. The Ti(3)-O(5) bond length is 1.99 Å. In the fourth Ti site, Ti(4) is bonded to one O(11), one O(12), one O(14), one O(3), one O(7), and one O(9) atom to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 11-18°. The Ti(4)-O(11) bond length is 1.98 Å. The Ti(4)-O(12) bond length is 1.95 Å. The Ti(4)-O(14) bond length is 2.00 Å. The Ti(4)-O(3) bond length is 1.93 Å. The Ti(4)-O(7) bond length is 1.97 Å. The Ti(4)-O(9) bond length is 2.00 Å. In the fifth Ti site, Ti(5) is bonded to one O(8), one O(9), two equivalent O(10), and two equivalent O(6) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 14-20°. The Ti(5)-O(8) bond length is 1.95 Å. The Ti(5)-O(9) bond length is 1.98 Å. There is one shorter (1.92 Å) and one longer (1.99 Å) Ti(5)-O(10) bond length. There is one shorter (1.98 Å) and one longer (2.02 Å) Ti(5)-O(6) bond length. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Na(1), one Sr(1), one Sr(2), one La(2), one Ti(2), and one Ti(3) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), one La(1), one La(2), one Ti(1), and one Ti(4) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Na(1), one Sr(1), one Sr(2), one La(2), one Ti(2), and one Ti(3) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Na(1), two equivalent La(2), one Ti(1), and one Ti(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Na(2), two equivalent La(1), and two equivalent Ti(5) atoms. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Na(1), one La(1), one La(2), one Ti(1), and one Ti(4) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Na(2), two equivalent La(1), one Ti(1), and one Ti(5) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Na(2), two equivalent La(1), one Ti(4), and one Ti(5) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Na(2), two equivalent La(1), and two equivalent Ti(5) atoms. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), one La(1), one La(2), one Ti(1), and one Ti(4) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to two equivalent Na(1), two equivalent La(2), one Ti(2), and one Ti(4) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Na(1), one Sr(1), one Sr(2), one La(2), one Ti(2), and one Ti(3) atom. In the fourteenth O site, O(14) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one La(1), one La(2), one Ti(1), and one Ti(4) atom. In the fifteenth O site, O(15) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Ti(3) atoms. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to one Na(1), one Sr(1), one Sr(2), one La(2), one Ti(2), and one Ti(3) atom.