The material structure described by Ba4Ti11O26 crystallizes in the triclinic P1 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 11-coordinate geometry to one O(11), one O(12), one O(15), one O(16), one O(18), one O(20), one O(21), one O(22), one O(25), one O(26), and one O(3) atom. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one O(11), one O(12), one O(15), one O(16), one O(17), one O(19), one O(21), one O(22), one O(25), one O(26), and one O(4) atom. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(14), one O(23), one O(24), and one O(9) atom. In the fourth Ba site, Ba(4) is bonded in a 11-coordinate geometry to one O(10), one O(13), one O(14), one O(17), one O(19), one O(2), one O(23), one O(24), one O(25), one O(26), and one O(9) atom. There are eleven inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(11), one O(23), one O(5), one O(6), and one O(7) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 24-25°. In the second Ti site, Ti(2) is bonded to one O(12), one O(2), one O(24), one O(5), one O(6), and one O(8) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 24-25°. In the third Ti site, Ti(3) is bonded to one O(21), one O(3), one O(5), one O(7), one O(8), and one O(9) atom to form distorted edge-sharing TiO6 octahedra. In the fourth Ti site, Ti(4) is bonded in a 6-coordinate geometry to one O(10), one O(22), one O(4), one O(6), one O(7), and one O(8) atom. In the fifth Ti site, Ti(5) is bonded to one O(1), one O(16), one O(17), one O(18), one O(23), and one O(26) atom to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 9-16°. In the sixth Ti site, Ti(6) is bonded to one O(15), one O(17), one O(18), one O(2), one O(24), and one O(25) atom to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 10-15°. In the seventh Ti site, Ti(7) is bonded to one O(14), one O(19), one O(20), one O(21), one O(25), and one O(3) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 15-22°. In the eighth Ti site, Ti(8) is bonded to one O(13), one O(19), one O(20), one O(22), one O(26), and one O(4) atom to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 9-22°. In the ninth Ti site, Ti(9) is bonded to one O(1), one O(13), one O(17), one O(2), one O(5), and one O(9) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the tenth Ti site, Ti(10) is bonded to one O(12), one O(16), one O(20), one O(3), one O(4), and one O(8) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 16-24°. In the eleventh Ti site, Ti(11) is bonded to one O(11), one O(15), one O(19), one O(3), one O(4), and one O(7) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 12-24°. There are twenty-six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ti(1), one Ti(5), and one Ti(9) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ba(4), one Ti(2), one Ti(6), and one Ti(9) atom. In the third O site, O(3) is bonded to one Ba(1), one Ti(10), one Ti(11), one Ti(3), and one Ti(7) atom to form distorted edge-sharing OBaTi4 trigonal pyramids. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ba(2), one Ti(10), one Ti(11), one Ti(4), and one Ti(8) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Ti(1), one Ti(2), one Ti(3), and one Ti(9) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(2), and one Ti(4) atom. In the seventh O site, O(7) is bonded to one Ti(1), one Ti(11), one Ti(3), and one Ti(4) atom to form OTi4 trigonal pyramids that share corners with two equivalent O(8)Ti4 trigonal pyramids and  an edgeedge with one O(3)BaTi4 trigonal pyramid. In the eighth O site, O(8) is bonded to one Ti(10), one Ti(2), one Ti(3), and one Ti(4) atom to form OTi4 trigonal pyramids that share corners with two equivalent O(7)Ti4 trigonal pyramids and  an edgeedge with one O(3)BaTi4 trigonal pyramid. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Ba(3), one Ba(4), one Ti(3), and one Ti(9) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Ba(3), one Ba(4), and one Ti(4) atom. In the eleventh O site, O(11) is bonded in a distorted water-like geometry to one Ba(1), one Ba(2), one Ti(1), and one Ti(11) atom. In the twelfth O site, O(12) is bonded in a distorted water-like geometry to one Ba(1), one Ba(2), one Ti(10), and one Ti(2) atom. In the thirteenth O site, O(13) is bonded in a distorted rectangular see-saw-like geometry to one Ba(3), one Ba(4), one Ti(8), and one Ti(9) atom. In the fourteenth O site, O(14) is bonded in a distorted single-bond geometry to one Ba(3), one Ba(4), and one Ti(7) atom. In the fifteenth O site, O(15) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ti(11), and one Ti(6) atom. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to one Ba(1), one Ba(2), one Ti(10), and one Ti(5) atom. In the seventeenth O site, O(17) is bonded in a distorted T-shaped geometry to one Ba(2), one Ba(4), one Ti(5), one Ti(6), and one Ti(9) atom. In the eighteenth O site, O(18) is bonded in a distorted linear geometry to one Ba(1), one Ti(5), and one Ti(6) atom. In the nineteenth O site, O(19) is bonded in a distorted T-shaped geometry to one Ba(2), one Ba(4), one Ti(11), one Ti(7), and one Ti(8) atom. In the twentieth O site, O(20) is bonded in a distorted T-shaped geometry to one Ba(1), one Ti(10), one Ti(7), and one Ti(8) atom. In the twenty-first O site, O(21) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Ti(3), and one Ti(7) atom. In the twenty-second O site, O(22) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Ti(4), and one Ti(8) atom. In the twenty-third O site, O(23) is bonded in a 4-coordinate geometry to one Ba(3), one Ba(4), one Ti(1), and one Ti(5) atom. In the twenty-fourth O site, O(24) is bonded in a 4-coordinate geometry to one Ba(3), one Ba(4), one Ti(2), and one Ti(6) atom. In the twenty-fifth O site, O(25) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(4), one Ti(6), and one Ti(7) atom. In the twenty-sixth O site, O(26) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(4), one Ti(5), and one Ti(8) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba4Ti11O26
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.858
_cell_length_b   7.920
_cell_length_c   10.046
_cell_angle_alpha   76.162
_cell_angle_beta   67.000
_cell_angle_gamma   75.703
_symmetry_Int_Tables_number   1
_cell_volume   550.495
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ba  Ba0  1  0.861  0.093  0.231  1.0
  Ba  Ba1  1  0.365  0.096  0.222  1.0
  Ba  Ba2  1  0.143  0.878  0.763  1.0
  Ba  Ba3  1  0.653  0.886  0.765  1.0
  Ti  Ti4  1  0.374  0.345  0.565  1.0
  Ti  Ti5  1  0.888  0.346  0.567  1.0
  Ti  Ti6  1  0.614  0.663  0.441  1.0
  Ti  Ti7  1  0.109  0.666  0.449  1.0
  Ti  Ti8  1  0.227  0.251  0.894  1.0
  Ti  Ti9  1  0.753  0.244  0.900  1.0
  Ti  Ti10  1  0.767  0.760  0.085  1.0
  Ti  Ti11  1  0.262  0.767  0.093  1.0
  Ti  Ti12  1  0.488  0.507  0.777  1.0
  Ti  Ti13  1  0.017  0.476  0.230  1.0
  Ti  Ti14  1  0.514  0.478  0.230  1.0
  O  O15  1  0.263  0.465  0.758  1.0
  O  O16  1  0.745  0.466  0.758  1.0
  O  O17  1  0.748  0.527  0.242  1.0
  O  O18  1  0.255  0.511  0.234  1.0
  O  O19  1  0.614  0.400  0.572  1.0
  O  O20  1  0.122  0.402  0.554  1.0
  O  O21  1  0.385  0.600  0.431  1.0
  O  O22  1  0.884  0.600  0.431  1.0
  O  O23  1  0.506  0.734  0.621  1.0
  O  O24  1  0.007  0.793  0.588  1.0
  O  O25  1  0.498  0.267  0.382  1.0
  O  O26  1  0.986  0.269  0.382  1.0
  O  O27  1  0.379  0.660  0.913  1.0
  O  O28  1  0.868  0.692  0.917  1.0
  O  O29  1  0.628  0.344  0.086  1.0
  O  O30  1  0.116  0.339  0.087  1.0
  O  O31  1  0.483  0.271  0.896  1.0
  O  O32  1  0.989  0.227  0.910  1.0
  O  O33  1  0.507  0.724  0.119  1.0
  O  O34  1  0.012  0.728  0.116  1.0
  O  O35  1  0.628  0.863  0.311  1.0
  O  O36  1  0.145  0.849  0.286  1.0
  O  O37  1  0.355  0.145  0.705  1.0
  O  O38  1  0.866  0.146  0.706  1.0
  O  O39  1  0.728  0.008  0.011  1.0
  O  O40  1  0.263  0.996  1.000  1.0
[/CIF]
.
The material structure described by Ba4Ti11O26 crystallizes in the triclinic P1 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 11-coordinate geometry to one O(11), one O(12), one O(15), one O(16), one O(18), one O(20), one O(21), one O(22), one O(25), one O(26), and one O(3) atom. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one O(11), one O(12), one O(15), one O(16), one O(17), one O(19), one O(21), one O(22), one O(25), one O(26), and one O(4) atom. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(14), one O(23), one O(24), and one O(9) atom. In the fourth Ba site, Ba(4) is bonded in a 11-coordinate geometry to one O(10), one O(13), one O(14), one O(17), one O(19), one O(2), one O(23), one O(24), one O(25), one O(26), and one O(9) atom. There are eleven inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(11), one O(23), one O(5), one O(6), and one O(7) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 24-25°. In the second Ti site, Ti(2) is bonded to one O(12), one O(2), one O(24), one O(5), one O(6), and one O(8) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 24-25°. In the third Ti site, Ti(3) is bonded to one O(21), one O(3), one O(5), one O(7), one O(8), and one O(9) atom to form distorted edge-sharing TiO6 octahedra. In the fourth Ti site, Ti(4) is bonded in a 6-coordinate geometry to one O(10), one O(22), one O(4), one O(6), one O(7), and one O(8) atom. In the fifth Ti site, Ti(5) is bonded to one O(1), one O(16), one O(17), one O(18), one O(23), and one O(26) atom to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 9-16°. In the sixth Ti site, Ti(6) is bonded to one O(15), one O(17), one O(18), one O(2), one O(24), and one O(25) atom to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 10-15°. In the seventh Ti site, Ti(7) is bonded to one O(14), one O(19), one O(20), one O(21), one O(25), and one O(3) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 15-22°. In the eighth Ti site, Ti(8) is bonded to one O(13), one O(19), one O(20), one O(22), one O(26), and one O(4) atom to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 9-22°. In the ninth Ti site, Ti(9) is bonded to one O(1), one O(13), one O(17), one O(2), one O(5), and one O(9) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the tenth Ti site, Ti(10) is bonded to one O(12), one O(16), one O(20), one O(3), one O(4), and one O(8) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 16-24°. In the eleventh Ti site, Ti(11) is bonded to one O(11), one O(15), one O(19), one O(3), one O(4), and one O(7) atom to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 12-24°. There are twenty-six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ti(1), one Ti(5), and one Ti(9) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ba(4), one Ti(2), one Ti(6), and one Ti(9) atom. In the third O site, O(3) is bonded to one Ba(1), one Ti(10), one Ti(11), one Ti(3), and one Ti(7) atom to form distorted edge-sharing OBaTi4 trigonal pyramids. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ba(2), one Ti(10), one Ti(11), one Ti(4), and one Ti(8) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Ti(1), one Ti(2), one Ti(3), and one Ti(9) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(2), and one Ti(4) atom. In the seventh O site, O(7) is bonded to one Ti(1), one Ti(11), one Ti(3), and one Ti(4) atom to form OTi4 trigonal pyramids that share corners with two equivalent O(8)Ti4 trigonal pyramids and  an edgeedge with one O(3)BaTi4 trigonal pyramid. In the eighth O site, O(8) is bonded to one Ti(10), one Ti(2), one Ti(3), and one Ti(4) atom to form OTi4 trigonal pyramids that share corners with two equivalent O(7)Ti4 trigonal pyramids and  an edgeedge with one O(3)BaTi4 trigonal pyramid. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Ba(3), one Ba(4), one Ti(3), and one Ti(9) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Ba(3), one Ba(4), and one Ti(4) atom. In the eleventh O site, O(11) is bonded in a distorted water-like geometry to one Ba(1), one Ba(2), one Ti(1), and one Ti(11) atom. In the twelfth O site, O(12) is bonded in a distorted water-like geometry to one Ba(1), one Ba(2), one Ti(10), and one Ti(2) atom. In the thirteenth O site, O(13) is bonded in a distorted rectangular see-saw-like geometry to one Ba(3), one Ba(4), one Ti(8), and one Ti(9) atom. In the fourteenth O site, O(14) is bonded in a distorted single-bond geometry to one Ba(3), one Ba(4), and one Ti(7) atom. In the fifteenth O site, O(15) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ti(11), and one Ti(6) atom. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to one Ba(1), one Ba(2), one Ti(10), and one Ti(5) atom. In the seventeenth O site, O(17) is bonded in a distorted T-shaped geometry to one Ba(2), one Ba(4), one Ti(5), one Ti(6), and one Ti(9) atom. In the eighteenth O site, O(18) is bonded in a distorted linear geometry to one Ba(1), one Ti(5), and one Ti(6) atom. In the nineteenth O site, O(19) is bonded in a distorted T-shaped geometry to one Ba(2), one Ba(4), one Ti(11), one Ti(7), and one Ti(8) atom. In the twentieth O site, O(20) is bonded in a distorted T-shaped geometry to one Ba(1), one Ti(10), one Ti(7), and one Ti(8) atom. In the twenty-first O site, O(21) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Ti(3), and one Ti(7) atom. In the twenty-second O site, O(22) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Ti(4), and one Ti(8) atom. In the twenty-third O site, O(23) is bonded in a 4-coordinate geometry to one Ba(3), one Ba(4), one Ti(1), and one Ti(5) atom. In the twenty-fourth O site, O(24) is bonded in a 4-coordinate geometry to one Ba(3), one Ba(4), one Ti(2), and one Ti(6) atom. In the twenty-fifth O site, O(25) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(4), one Ti(6), and one Ti(7) atom. In the twenty-sixth O site, O(26) is bonded in a distorted linear geometry to one Ba(1), one Ba(2), one Ba(4), one Ti(5), and one Ti(8) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba4Ti11O26
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.858
_cell_length_b   7.920
_cell_length_c   10.046
_cell_angle_alpha   76.162
_cell_angle_beta   67.000
_cell_angle_gamma   75.703
_symmetry_Int_Tables_number   1
_cell_volume   550.495
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ba  Ba0  1  0.861  0.093  0.231  1.0
  Ba  Ba1  1  0.365  0.096  0.222  1.0
  Ba  Ba2  1  0.143  0.878  0.763  1.0
  Ba  Ba3  1  0.653  0.886  0.765  1.0
  Ti  Ti4  1  0.374  0.345  0.565  1.0
  Ti  Ti5  1  0.888  0.346  0.567  1.0
  Ti  Ti6  1  0.614  0.663  0.441  1.0
  Ti  Ti7  1  0.109  0.666  0.449  1.0
  Ti  Ti8  1  0.227  0.251  0.894  1.0
  Ti  Ti9  1  0.753  0.244  0.900  1.0
  Ti  Ti10  1  0.767  0.760  0.085  1.0
  Ti  Ti11  1  0.262  0.767  0.093  1.0
  Ti  Ti12  1  0.488  0.507  0.777  1.0
  Ti  Ti13  1  0.017  0.476  0.230  1.0
  Ti  Ti14  1  0.514  0.478  0.230  1.0
  O  O15  1  0.263  0.465  0.758  1.0
  O  O16  1  0.745  0.466  0.758  1.0
  O  O17  1  0.748  0.527  0.242  1.0
  O  O18  1  0.255  0.511  0.234  1.0
  O  O19  1  0.614  0.400  0.572  1.0
  O  O20  1  0.122  0.402  0.554  1.0
  O  O21  1  0.385  0.600  0.431  1.0
  O  O22  1  0.884  0.600  0.431  1.0
  O  O23  1  0.506  0.734  0.621  1.0
  O  O24  1  0.007  0.793  0.588  1.0
  O  O25  1  0.498  0.267  0.382  1.0
  O  O26  1  0.986  0.269  0.382  1.0
  O  O27  1  0.379  0.660  0.913  1.0
  O  O28  1  0.868  0.692  0.917  1.0
  O  O29  1  0.628  0.344  0.086  1.0
  O  O30  1  0.116  0.339  0.087  1.0
  O  O31  1  0.483  0.271  0.896  1.0
  O  O32  1  0.989  0.227  0.910  1.0
  O  O33  1  0.507  0.724  0.119  1.0
  O  O34  1  0.012  0.728  0.116  1.0
  O  O35  1  0.628  0.863  0.311  1.0
  O  O36  1  0.145  0.849  0.286  1.0
  O  O37  1  0.355  0.145  0.705  1.0
  O  O38  1  0.866  0.146  0.706  1.0
  O  O39  1  0.728  0.008  0.011  1.0
  O  O40  1  0.263  0.996  1.000  1.0
[/CIF]
.