The material described by K2Na2BaTi4(SiO4)8 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(10), one O(13), one O(9), two equivalent O(18), and two equivalent O(7) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(10), one O(14), one O(9), two equivalent O(18), and two equivalent O(8) atoms. Na(1) is bonded to one O(11), one O(16), one O(17), one O(18), one O(4), and one O(6) atom to form distorted NaO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-64°. Ba(1) is bonded in a 11-coordinate geometry to one O(13), two equivalent O(1), two equivalent O(17), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(15), one O(16), one O(3), one O(4), one O(7), and one O(8) atom to form TiO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-64°. In the second Ti site, Ti(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(11), one O(13), and one O(15) atom to form SiO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 39-75°. In the second Si site, Si(2) is bonded to one O(12), one O(14), one O(16), and one O(2) atom to form SiO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-67°. In the third Si site, Si(3) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-64°. In the fourth Si site, Si(4) is bonded to one O(10), one O(12), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-61°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Ba(1), one Ti(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ti(2), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ti(1), and one Ti(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Na(1), one Ti(1), and one Ti(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ti(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Ti(2), and one Si(4) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one K(1), one Ba(1), one Ti(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one K(2), one Ti(1), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), and two equivalent Si(3) atoms. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), and two equivalent Si(4) atoms. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Si(1), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 150 degrees geometry to one K(1), one Ba(1), and two equivalent Si(1) atoms. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one K(2) and two equivalent Si(2) atoms. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Ti(1) and one Si(1) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Na(1), one Ti(1), and one Si(2) atom. In the seventeenth O site, O(17) is bonded in a 2-coordinate geometry to one Na(1) and one Ba(1) atom. In the eighteenth O site, O(18) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one K(2), and one Na(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2BaNa2Ti4(SiO4)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.085
_cell_length_b   10.085
_cell_length_c   7.866
_cell_angle_alpha   70.551
_cell_angle_beta   70.551
_cell_angle_gamma   88.591
_symmetry_Int_Tables_number   1
_cell_volume   708.028
_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
  K  K0  1  0.581  0.581  0.688  1.0
  K  K1  1  0.420  0.420  0.297  1.0
  Ba  Ba2  1  0.913  0.913  0.367  1.0
  Na  Na3  1  0.689  0.190  0.968  1.0
  Na  Na4  1  0.190  0.689  0.968  1.0
  Ti  Ti5  1  0.994  0.479  0.502  1.0
  Ti  Ti6  1  0.479  0.994  0.502  1.0
  Ti  Ti7  1  0.232  0.776  0.497  1.0
  Ti  Ti8  1  0.776  0.232  0.497  1.0
  Si  Si9  1  0.890  0.666  0.808  1.0
  Si  Si10  1  0.666  0.890  0.808  1.0
  Si  Si11  1  0.318  0.102  0.190  1.0
  Si  Si12  1  0.102  0.318  0.190  1.0
  Si  Si13  1  0.789  0.566  0.249  1.0
  Si  Si14  1  0.566  0.789  0.249  1.0
  Si  Si15  1  0.440  0.218  0.739  1.0
  Si  Si16  1  0.218  0.440  0.739  1.0
  O  O17  1  0.028  0.775  0.655  1.0
  O  O18  1  0.775  0.028  0.655  1.0
  O  O19  1  0.204  0.962  0.313  1.0
  O  O20  1  0.962  0.204  0.313  1.0
  O  O21  1  0.118  0.681  0.390  1.0
  O  O22  1  0.681  0.118  0.390  1.0
  O  O23  1  0.313  0.883  0.597  1.0
  O  O24  1  0.883  0.313  0.597  1.0
  O  O25  1  0.752  0.397  0.308  1.0
  O  O26  1  0.397  0.752  0.308  1.0
  O  O27  1  0.607  0.249  0.699  1.0
  O  O28  1  0.249  0.607  0.699  1.0
  O  O29  1  0.858  0.602  0.390  1.0
  O  O30  1  0.602  0.858  0.390  1.0
  O  O31  1  0.416  0.145  0.595  1.0
  O  O32  1  0.145  0.416  0.595  1.0
  O  O33  1  0.636  0.636  0.272  1.0
  O  O34  1  0.375  0.375  0.696  1.0
  O  O35  1  0.895  0.638  0.023  1.0
  O  O36  1  0.638  0.895  0.023  1.0
  O  O37  1  0.362  0.123  0.963  1.0
  O  O38  1  0.123  0.362  0.963  1.0
  O  O39  1  0.750  0.750  0.781  1.0
  O  O40  1  0.244  0.244  0.222  1.0
  O  O41  1  0.890  0.527  0.748  1.0
  O  O42  1  0.527  0.890  0.748  1.0
  O  O43  1  0.458  0.093  0.254  1.0
  O  O44  1  0.093  0.458  0.254  1.0
  O  O45  1  0.141  0.843  0.140  1.0
  O  O46  1  0.843  0.141  0.140  1.0
  O  O47  1  0.688  0.426  0.982  1.0
  O  O48  1  0.426  0.688  0.982  1.0
[/CIF]
.
The material described by K2Na2BaTi4(SiO4)8 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(10), one O(13), one O(9), two equivalent O(18), and two equivalent O(7) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(10), one O(14), one O(9), two equivalent O(18), and two equivalent O(8) atoms. Na(1) is bonded to one O(11), one O(16), one O(17), one O(18), one O(4), and one O(6) atom to form distorted NaO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-64°. Ba(1) is bonded in a 11-coordinate geometry to one O(13), two equivalent O(1), two equivalent O(17), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(15), one O(16), one O(3), one O(4), one O(7), and one O(8) atom to form TiO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-64°. In the second Ti site, Ti(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(11), one O(13), and one O(15) atom to form SiO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 39-75°. In the second Si site, Si(2) is bonded to one O(12), one O(14), one O(16), and one O(2) atom to form SiO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-67°. In the third Si site, Si(3) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-64°. In the fourth Si site, Si(4) is bonded to one O(10), one O(12), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-61°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Ba(1), one Ti(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ti(2), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ti(1), and one Ti(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Na(1), one Ti(1), and one Ti(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ti(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Ti(2), and one Si(4) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one K(1), one Ba(1), one Ti(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one K(2), one Ti(1), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), and two equivalent Si(3) atoms. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), and two equivalent Si(4) atoms. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Si(1), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 150 degrees geometry to one K(1), one Ba(1), and two equivalent Si(1) atoms. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one K(2) and two equivalent Si(2) atoms. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Ti(1) and one Si(1) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Na(1), one Ti(1), and one Si(2) atom. In the seventeenth O site, O(17) is bonded in a 2-coordinate geometry to one Na(1) and one Ba(1) atom. In the eighteenth O site, O(18) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one K(2), and one Na(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2BaNa2Ti4(SiO4)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.085
_cell_length_b   10.085
_cell_length_c   7.866
_cell_angle_alpha   70.551
_cell_angle_beta   70.551
_cell_angle_gamma   88.591
_symmetry_Int_Tables_number   1
_cell_volume   708.028
_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
  K  K0  1  0.581  0.581  0.688  1.0
  K  K1  1  0.420  0.420  0.297  1.0
  Ba  Ba2  1  0.913  0.913  0.367  1.0
  Na  Na3  1  0.689  0.190  0.968  1.0
  Na  Na4  1  0.190  0.689  0.968  1.0
  Ti  Ti5  1  0.994  0.479  0.502  1.0
  Ti  Ti6  1  0.479  0.994  0.502  1.0
  Ti  Ti7  1  0.232  0.776  0.497  1.0
  Ti  Ti8  1  0.776  0.232  0.497  1.0
  Si  Si9  1  0.890  0.666  0.808  1.0
  Si  Si10  1  0.666  0.890  0.808  1.0
  Si  Si11  1  0.318  0.102  0.190  1.0
  Si  Si12  1  0.102  0.318  0.190  1.0
  Si  Si13  1  0.789  0.566  0.249  1.0
  Si  Si14  1  0.566  0.789  0.249  1.0
  Si  Si15  1  0.440  0.218  0.739  1.0
  Si  Si16  1  0.218  0.440  0.739  1.0
  O  O17  1  0.028  0.775  0.655  1.0
  O  O18  1  0.775  0.028  0.655  1.0
  O  O19  1  0.204  0.962  0.313  1.0
  O  O20  1  0.962  0.204  0.313  1.0
  O  O21  1  0.118  0.681  0.390  1.0
  O  O22  1  0.681  0.118  0.390  1.0
  O  O23  1  0.313  0.883  0.597  1.0
  O  O24  1  0.883  0.313  0.597  1.0
  O  O25  1  0.752  0.397  0.308  1.0
  O  O26  1  0.397  0.752  0.308  1.0
  O  O27  1  0.607  0.249  0.699  1.0
  O  O28  1  0.249  0.607  0.699  1.0
  O  O29  1  0.858  0.602  0.390  1.0
  O  O30  1  0.602  0.858  0.390  1.0
  O  O31  1  0.416  0.145  0.595  1.0
  O  O32  1  0.145  0.416  0.595  1.0
  O  O33  1  0.636  0.636  0.272  1.0
  O  O34  1  0.375  0.375  0.696  1.0
  O  O35  1  0.895  0.638  0.023  1.0
  O  O36  1  0.638  0.895  0.023  1.0
  O  O37  1  0.362  0.123  0.963  1.0
  O  O38  1  0.123  0.362  0.963  1.0
  O  O39  1  0.750  0.750  0.781  1.0
  O  O40  1  0.244  0.244  0.222  1.0
  O  O41  1  0.890  0.527  0.748  1.0
  O  O42  1  0.527  0.890  0.748  1.0
  O  O43  1  0.458  0.093  0.254  1.0
  O  O44  1  0.093  0.458  0.254  1.0
  O  O45  1  0.141  0.843  0.140  1.0
  O  O46  1  0.843  0.141  0.140  1.0
  O  O47  1  0.688  0.426  0.982  1.0
  O  O48  1  0.426  0.688  0.982  1.0
[/CIF]
.