The material described by Ca4Mg4P4O17F3 crystallizes in the monoclinic C2 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(9), two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(5), two equivalent O(8), and one F(1) atom. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one F(2) atom. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), one O(3), one O(6), one O(8), one F(1), and one F(2) atom to form MgO4F2 octahedra that share  a cornercorner with one Mg(1)O4F2 octahedra,  a cornercorner with one Mg(2)O5F octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. In the second Mg site, Mg(2) is bonded to one O(1), one O(4), one O(5), one O(7), one O(9), and one F(2) atom to form MgO5F octahedra that share  a cornercorner with one Mg(1)O4F2 octahedra,  a cornercorner with one Mg(2)O5F octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-46°. There are three inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(2) and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with two equivalent Mg(1)O4F2 octahedra and corners with two equivalent Mg(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 39-53°. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with two equivalent Mg(1)O4F2 octahedra and corners with two equivalent Mg(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 38-53°. In the third P site, P(3) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O4F2 octahedra and corners with two equivalent Mg(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 39-53°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(2), one Mg(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Mg(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(3), one Mg(1), and one P(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(3), one Mg(2), and one P(3) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Mg(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), one Mg(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), one Mg(2), and one P(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Mg(1), and one P(3) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Mg(2) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a trigonal planar geometry to one Ca(2) and two equivalent Mg(1) atoms. In the second F site, F(2) is bonded in a trigonal planar geometry to one Ca(3), one Mg(1), and one Mg(2) atom. is represented by the CIF file [CIF]
data_Ca4Mg4P4O17F3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.932
_cell_length_b   7.932
_cell_length_c   6.601
_cell_angle_alpha   85.489
_cell_angle_beta   85.489
_cell_angle_gamma   67.615
_symmetry_Int_Tables_number   1
_cell_volume   382.316
_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
  Ca  Ca0  1  0.213  0.787  0.500  1.0
  Ca  Ca1  1  0.711  0.289  0.000  1.0
  Ca  Ca2  1  0.787  0.712  0.251  1.0
  Ca  Ca3  1  0.288  0.213  0.749  1.0
  Mg  Mg4  1  0.250  0.499  0.125  1.0
  Mg  Mg5  1  0.747  0.999  0.624  1.0
  Mg  Mg6  1  0.001  0.253  0.376  1.0
  Mg  Mg7  1  0.501  0.750  0.875  1.0
  P  P8  1  0.554  0.446  0.500  1.0
  P  P9  1  0.055  0.945  0.000  1.0
  P  P10  1  0.446  0.054  0.250  1.0
  P  P11  1  0.946  0.554  0.750  1.0
  O  O12  1  0.869  0.975  0.908  1.0
  O  O13  1  0.369  0.475  0.408  1.0
  O  O14  1  0.025  0.131  0.092  1.0
  O  O15  1  0.525  0.631  0.592  1.0
  O  O16  1  0.131  0.525  0.842  1.0
  O  O17  1  0.632  0.024  0.340  1.0
  O  O18  1  0.976  0.368  0.660  1.0
  O  O19  1  0.475  0.869  0.158  1.0
  O  O20  1  0.713  0.404  0.333  1.0
  O  O21  1  0.214  0.904  0.834  1.0
  O  O22  1  0.596  0.287  0.667  1.0
  O  O23  1  0.096  0.786  0.166  1.0
  O  O24  1  0.288  0.098  0.416  1.0
  O  O25  1  0.786  0.597  0.917  1.0
  O  O26  1  0.403  0.214  0.083  1.0
  O  O27  1  0.902  0.712  0.584  1.0
  O  O28  1  0.960  0.040  0.500  1.0
  F  F29  1  0.458  0.542  0.000  1.0
  F  F30  1  0.042  0.459  0.249  1.0
  F  F31  1  0.541  0.958  0.751  1.0
[/CIF]
.
The material described by Ca4Mg4P4O17F3 crystallizes in the monoclinic C2 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(9), two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(5), two equivalent O(8), and one F(1) atom. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one F(2) atom. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(2), one O(3), one O(6), one O(8), one F(1), and one F(2) atom to form MgO4F2 octahedra that share  a cornercorner with one Mg(1)O4F2 octahedra,  a cornercorner with one Mg(2)O5F octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. In the second Mg site, Mg(2) is bonded to one O(1), one O(4), one O(5), one O(7), one O(9), and one F(2) atom to form MgO5F octahedra that share  a cornercorner with one Mg(1)O4F2 octahedra,  a cornercorner with one Mg(2)O5F octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-46°. There are three inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(2) and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with two equivalent Mg(1)O4F2 octahedra and corners with two equivalent Mg(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 39-53°. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with two equivalent Mg(1)O4F2 octahedra and corners with two equivalent Mg(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 38-53°. In the third P site, P(3) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O4F2 octahedra and corners with two equivalent Mg(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 39-53°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(2), one Mg(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Mg(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(3), one Mg(1), and one P(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(3), one Mg(2), and one P(3) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Mg(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), one Mg(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), one Mg(2), and one P(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Mg(1), and one P(3) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Mg(2) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a trigonal planar geometry to one Ca(2) and two equivalent Mg(1) atoms. In the second F site, F(2) is bonded in a trigonal planar geometry to one Ca(3), one Mg(1), and one Mg(2) atom. is represented by the CIF file [CIF]
data_Ca4Mg4P4O17F3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.932
_cell_length_b   7.932
_cell_length_c   6.601
_cell_angle_alpha   85.489
_cell_angle_beta   85.489
_cell_angle_gamma   67.615
_symmetry_Int_Tables_number   1
_cell_volume   382.316
_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
  Ca  Ca0  1  0.213  0.787  0.500  1.0
  Ca  Ca1  1  0.711  0.289  0.000  1.0
  Ca  Ca2  1  0.787  0.712  0.251  1.0
  Ca  Ca3  1  0.288  0.213  0.749  1.0
  Mg  Mg4  1  0.250  0.499  0.125  1.0
  Mg  Mg5  1  0.747  0.999  0.624  1.0
  Mg  Mg6  1  0.001  0.253  0.376  1.0
  Mg  Mg7  1  0.501  0.750  0.875  1.0
  P  P8  1  0.554  0.446  0.500  1.0
  P  P9  1  0.055  0.945  0.000  1.0
  P  P10  1  0.446  0.054  0.250  1.0
  P  P11  1  0.946  0.554  0.750  1.0
  O  O12  1  0.869  0.975  0.908  1.0
  O  O13  1  0.369  0.475  0.408  1.0
  O  O14  1  0.025  0.131  0.092  1.0
  O  O15  1  0.525  0.631  0.592  1.0
  O  O16  1  0.131  0.525  0.842  1.0
  O  O17  1  0.632  0.024  0.340  1.0
  O  O18  1  0.976  0.368  0.660  1.0
  O  O19  1  0.475  0.869  0.158  1.0
  O  O20  1  0.713  0.404  0.333  1.0
  O  O21  1  0.214  0.904  0.834  1.0
  O  O22  1  0.596  0.287  0.667  1.0
  O  O23  1  0.096  0.786  0.166  1.0
  O  O24  1  0.288  0.098  0.416  1.0
  O  O25  1  0.786  0.597  0.917  1.0
  O  O26  1  0.403  0.214  0.083  1.0
  O  O27  1  0.902  0.712  0.584  1.0
  O  O28  1  0.960  0.040  0.500  1.0
  F  F29  1  0.458  0.542  0.000  1.0
  F  F30  1  0.042  0.459  0.249  1.0
  F  F31  1  0.541  0.958  0.751  1.0
[/CIF]
.