The structure described by KCa12Si4S2O26F crystallizes in the trigonal R-3m space group. K(1) is bonded in a 6-coordinate geometry to six equivalent O(2) atoms. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(4), one O(6), one O(7), two equivalent O(2), and two equivalent O(5) atoms to form distorted CaO7 pentagonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one S(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with two equivalent Ca(1)O7 pentagonal bipyramids,  an edgeedge with one S(1)O4 tetrahedra, and faces with two equivalent Ca(1)O7 pentagonal bipyramids. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(1), one O(4), one O(5), three equivalent O(3), and one F(1) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(7) and three equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent Ca(1)O7 pentagonal bipyramids. In the second Si site, Si(2) is bonded to one O(1) and three equivalent O(5) atoms to form SiO4 tetrahedra that share corners with six equivalent Ca(1)O7 pentagonal bipyramids. S(1) is bonded to one O(6) and three equivalent O(2) atoms to form SO4 tetrahedra that share corners with three equivalent Ca(1)O7 pentagonal bipyramids and edges with three equivalent Ca(1)O7 pentagonal bipyramids. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ca(1) and one S(1) atom. In the second O site, O(7) is bonded to three equivalent Ca(1) and one Si(1) atom to form corner-sharing OCa3Si tetrahedra. The corner-sharing octahedral tilt angles are 59°. In the third O site, O(1) is bonded to three equivalent Ca(2) and one Si(2) atom to form distorted OCa3Si trigonal pyramids that share corners with three equivalent O(4)Ca6 octahedra and corners with three equivalent F(1)Ca6 octahedra. The corner-sharing octahedral tilt angles range from 26-47°. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to one K(1), two equivalent Ca(1), and one S(1) atom. In the fifth O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ca(2) and one Si(1) atom. In the sixth O site, O(4) is bonded to three equivalent Ca(1) and three equivalent Ca(2) atoms to form OCa6 octahedra that share corners with three equivalent O(7)Ca3Si tetrahedra, corners with three equivalent O(1)Ca3Si trigonal pyramids, and  a faceface with one F(1)Ca6 octahedra. In the seventh O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2), two equivalent Ca(1), and one Si(2) atom. F(1) is bonded to six equivalent Ca(2) atoms to form FCa6 octahedra that share corners with six equivalent O(1)Ca3Si trigonal pyramids and faces with two equivalent O(4)Ca6 octahedra. is represented by the CIF card [CIF]
data_KCa12Si4S2O26F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.497
_cell_length_b   14.497
_cell_length_c   14.497
_cell_angle_alpha   28.949
_cell_angle_beta   28.949
_cell_angle_gamma   28.949
_symmetry_Int_Tables_number   1
_cell_volume   631.377
_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  0.000  0.000  0.000  1.0
  Ca  Ca1  1  0.083  0.556  0.556  1.0
  Ca  Ca2  1  0.225  0.688  0.688  1.0
  Ca  Ca3  1  0.556  0.556  0.083  1.0
  Ca  Ca4  1  0.688  0.225  0.688  1.0
  Ca  Ca5  1  0.312  0.775  0.312  1.0
  Ca  Ca6  1  0.444  0.917  0.444  1.0
  Ca  Ca7  1  0.556  0.083  0.556  1.0
  Ca  Ca8  1  0.444  0.444  0.917  1.0
  Ca  Ca9  1  0.775  0.312  0.312  1.0
  Ca  Ca10  1  0.688  0.688  0.225  1.0
  Ca  Ca11  1  0.312  0.312  0.775  1.0
  Ca  Ca12  1  0.917  0.444  0.444  1.0
  Si  Si13  1  0.795  0.795  0.795  1.0
  Si  Si14  1  0.083  0.083  0.083  1.0
  Si  Si15  1  0.917  0.917  0.917  1.0
  Si  Si16  1  0.205  0.205  0.205  1.0
  S  S17  1  0.676  0.676  0.676  1.0
  S  S18  1  0.324  0.324  0.324  1.0
  O  O19  1  0.877  0.877  0.877  1.0
  O  O20  1  0.800  0.800  0.465  1.0
  O  O21  1  0.318  0.318  0.941  1.0
  O  O22  1  0.568  0.568  0.568  1.0
  O  O23  1  0.200  0.535  0.200  1.0
  O  O24  1  0.200  0.200  0.535  1.0
  O  O25  1  0.199  0.820  0.199  1.0
  O  O26  1  0.318  0.941  0.318  1.0
  O  O27  1  0.535  0.200  0.200  1.0
  O  O28  1  0.059  0.682  0.682  1.0
  O  O29  1  0.820  0.199  0.199  1.0
  O  O30  1  0.800  0.465  0.800  1.0
  O  O31  1  0.180  0.801  0.801  1.0
  O  O32  1  0.199  0.199  0.820  1.0
  O  O33  1  0.432  0.432  0.432  1.0
  O  O34  1  0.941  0.318  0.318  1.0
  O  O35  1  0.360  0.360  0.360  1.0
  O  O36  1  0.755  0.755  0.755  1.0
  O  O37  1  0.465  0.800  0.800  1.0
  O  O38  1  0.801  0.801  0.180  1.0
  O  O39  1  0.801  0.180  0.801  1.0
  O  O40  1  0.123  0.123  0.123  1.0
  O  O41  1  0.640  0.640  0.640  1.0
  O  O42  1  0.682  0.682  0.059  1.0
  O  O43  1  0.245  0.245  0.245  1.0
  O  O44  1  0.682  0.059  0.682  1.0
  F  F45  1  0.500  0.500  0.500  1.0
[/CIF]
.
The structure described by KCa12Si4S2O26F crystallizes in the trigonal R-3m space group. K(1) is bonded in a 6-coordinate geometry to six equivalent O(2) atoms. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(4), one O(6), one O(7), two equivalent O(2), and two equivalent O(5) atoms to form distorted CaO7 pentagonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one S(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with two equivalent Ca(1)O7 pentagonal bipyramids,  an edgeedge with one S(1)O4 tetrahedra, and faces with two equivalent Ca(1)O7 pentagonal bipyramids. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(1), one O(4), one O(5), three equivalent O(3), and one F(1) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(7) and three equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent Ca(1)O7 pentagonal bipyramids. In the second Si site, Si(2) is bonded to one O(1) and three equivalent O(5) atoms to form SiO4 tetrahedra that share corners with six equivalent Ca(1)O7 pentagonal bipyramids. S(1) is bonded to one O(6) and three equivalent O(2) atoms to form SO4 tetrahedra that share corners with three equivalent Ca(1)O7 pentagonal bipyramids and edges with three equivalent Ca(1)O7 pentagonal bipyramids. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ca(1) and one S(1) atom. In the second O site, O(7) is bonded to three equivalent Ca(1) and one Si(1) atom to form corner-sharing OCa3Si tetrahedra. The corner-sharing octahedral tilt angles are 59°. In the third O site, O(1) is bonded to three equivalent Ca(2) and one Si(2) atom to form distorted OCa3Si trigonal pyramids that share corners with three equivalent O(4)Ca6 octahedra and corners with three equivalent F(1)Ca6 octahedra. The corner-sharing octahedral tilt angles range from 26-47°. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to one K(1), two equivalent Ca(1), and one S(1) atom. In the fifth O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ca(2) and one Si(1) atom. In the sixth O site, O(4) is bonded to three equivalent Ca(1) and three equivalent Ca(2) atoms to form OCa6 octahedra that share corners with three equivalent O(7)Ca3Si tetrahedra, corners with three equivalent O(1)Ca3Si trigonal pyramids, and  a faceface with one F(1)Ca6 octahedra. In the seventh O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2), two equivalent Ca(1), and one Si(2) atom. F(1) is bonded to six equivalent Ca(2) atoms to form FCa6 octahedra that share corners with six equivalent O(1)Ca3Si trigonal pyramids and faces with two equivalent O(4)Ca6 octahedra. is represented by the CIF card [CIF]
data_KCa12Si4S2O26F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.497
_cell_length_b   14.497
_cell_length_c   14.497
_cell_angle_alpha   28.949
_cell_angle_beta   28.949
_cell_angle_gamma   28.949
_symmetry_Int_Tables_number   1
_cell_volume   631.377
_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  0.000  0.000  0.000  1.0
  Ca  Ca1  1  0.083  0.556  0.556  1.0
  Ca  Ca2  1  0.225  0.688  0.688  1.0
  Ca  Ca3  1  0.556  0.556  0.083  1.0
  Ca  Ca4  1  0.688  0.225  0.688  1.0
  Ca  Ca5  1  0.312  0.775  0.312  1.0
  Ca  Ca6  1  0.444  0.917  0.444  1.0
  Ca  Ca7  1  0.556  0.083  0.556  1.0
  Ca  Ca8  1  0.444  0.444  0.917  1.0
  Ca  Ca9  1  0.775  0.312  0.312  1.0
  Ca  Ca10  1  0.688  0.688  0.225  1.0
  Ca  Ca11  1  0.312  0.312  0.775  1.0
  Ca  Ca12  1  0.917  0.444  0.444  1.0
  Si  Si13  1  0.795  0.795  0.795  1.0
  Si  Si14  1  0.083  0.083  0.083  1.0
  Si  Si15  1  0.917  0.917  0.917  1.0
  Si  Si16  1  0.205  0.205  0.205  1.0
  S  S17  1  0.676  0.676  0.676  1.0
  S  S18  1  0.324  0.324  0.324  1.0
  O  O19  1  0.877  0.877  0.877  1.0
  O  O20  1  0.800  0.800  0.465  1.0
  O  O21  1  0.318  0.318  0.941  1.0
  O  O22  1  0.568  0.568  0.568  1.0
  O  O23  1  0.200  0.535  0.200  1.0
  O  O24  1  0.200  0.200  0.535  1.0
  O  O25  1  0.199  0.820  0.199  1.0
  O  O26  1  0.318  0.941  0.318  1.0
  O  O27  1  0.535  0.200  0.200  1.0
  O  O28  1  0.059  0.682  0.682  1.0
  O  O29  1  0.820  0.199  0.199  1.0
  O  O30  1  0.800  0.465  0.800  1.0
  O  O31  1  0.180  0.801  0.801  1.0
  O  O32  1  0.199  0.199  0.820  1.0
  O  O33  1  0.432  0.432  0.432  1.0
  O  O34  1  0.941  0.318  0.318  1.0
  O  O35  1  0.360  0.360  0.360  1.0
  O  O36  1  0.755  0.755  0.755  1.0
  O  O37  1  0.465  0.800  0.800  1.0
  O  O38  1  0.801  0.801  0.180  1.0
  O  O39  1  0.801  0.180  0.801  1.0
  O  O40  1  0.123  0.123  0.123  1.0
  O  O41  1  0.640  0.640  0.640  1.0
  O  O42  1  0.682  0.682  0.059  1.0
  O  O43  1  0.245  0.245  0.245  1.0
  O  O44  1  0.682  0.059  0.682  1.0
  F  F45  1  0.500  0.500  0.500  1.0
[/CIF]
.