The compound described by Ca3Si4(SbO7)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted CaO4 trigonal pyramids that share corners with two equivalent Sb(2)O6 octahedra, corners with four equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 73°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Sb(1)O6 octahedra,  a cornercorner with one Sb(2)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-50°. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Sb(1)O6 octahedra,  a cornercorner with one Sb(2)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Ca(2)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 63-71°. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted SbO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with two equivalent Sb(2)O6 octahedra, and  an edgeedge with one Ca(2)O4 trigonal pyramid. In the second Sb site, Sb(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form SbO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Ca(2)O4 trigonal pyramids, and edges with two equivalent Sb(1)O6 octahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Si(2), and one Sb(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(1), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(2), one Si(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ca(1), one Si(1), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Si(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(1), one Si(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Si4(SbO7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.923
_cell_length_b   9.923
_cell_length_c   10.732
_cell_angle_alpha   58.022
_cell_angle_beta   58.022
_cell_angle_gamma   47.819
_symmetry_Int_Tables_number   1
_cell_volume   638.340
_cell_formula_units_Z   2
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  0.251  0.158  0.533  1.0
  Ca  Ca1  1  0.842  0.749  0.967  1.0
  Ca  Ca2  1  0.158  0.251  0.033  1.0
  Ca  Ca3  1  0.641  0.359  0.250  1.0
  Ca  Ca4  1  0.749  0.842  0.467  1.0
  Ca  Ca5  1  0.359  0.641  0.750  1.0
  Si  Si6  1  0.087  0.534  0.666  1.0
  Si  Si7  1  0.534  0.087  0.166  1.0
  Si  Si8  1  0.250  0.492  0.136  1.0
  Si  Si9  1  0.492  0.250  0.636  1.0
  Si  Si10  1  0.466  0.913  0.834  1.0
  Si  Si11  1  0.750  0.508  0.864  1.0
  Si  Si12  1  0.508  0.750  0.364  1.0
  Si  Si13  1  0.913  0.466  0.334  1.0
  Sb  Sb14  1  0.219  0.781  0.250  1.0
  Sb  Sb15  1  0.781  0.219  0.750  1.0
  Sb  Sb16  1  0.000  0.000  0.000  1.0
  Sb  Sb17  1  0.000  0.000  0.500  1.0
  O  O18  1  0.330  0.849  0.502  1.0
  O  O19  1  0.890  0.960  0.746  1.0
  O  O20  1  0.604  0.515  0.832  1.0
  O  O21  1  0.960  0.890  0.246  1.0
  O  O22  1  0.950  0.272  0.479  1.0
  O  O23  1  0.483  0.084  0.806  1.0
  O  O24  1  0.515  0.604  0.332  1.0
  O  O25  1  0.728  0.050  0.021  1.0
  O  O26  1  0.517  0.916  0.194  1.0
  O  O27  1  0.710  0.649  0.402  1.0
  O  O28  1  0.110  0.040  0.254  1.0
  O  O29  1  0.050  0.728  0.521  1.0
  O  O30  1  0.916  0.517  0.694  1.0
  O  O31  1  0.849  0.330  0.002  1.0
  O  O32  1  0.649  0.710  0.902  1.0
  O  O33  1  0.272  0.950  0.979  1.0
  O  O34  1  0.473  0.922  0.677  1.0
  O  O35  1  0.290  0.351  0.598  1.0
  O  O36  1  0.078  0.527  0.823  1.0
  O  O37  1  0.351  0.290  0.098  1.0
  O  O38  1  0.084  0.483  0.306  1.0
  O  O39  1  0.040  0.110  0.754  1.0
  O  O40  1  0.922  0.473  0.177  1.0
  O  O41  1  0.396  0.485  0.168  1.0
  O  O42  1  0.527  0.078  0.323  1.0
  O  O43  1  0.485  0.396  0.668  1.0
  O  O44  1  0.151  0.670  0.998  1.0
  O  O45  1  0.670  0.151  0.498  1.0
[/CIF]
.
The compound described by Ca3Si4(SbO7)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted CaO4 trigonal pyramids that share corners with two equivalent Sb(2)O6 octahedra, corners with four equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 73°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Sb(1)O6 octahedra,  a cornercorner with one Sb(2)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-50°. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Sb(1)O6 octahedra,  a cornercorner with one Sb(2)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Ca(2)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 63-71°. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted SbO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with two equivalent Sb(2)O6 octahedra, and  an edgeedge with one Ca(2)O4 trigonal pyramid. In the second Sb site, Sb(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form SbO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Ca(2)O4 trigonal pyramids, and edges with two equivalent Sb(1)O6 octahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Si(2), and one Sb(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(1), one Sb(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(2), one Si(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ca(1), one Si(1), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Si(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(1), one Si(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Si4(SbO7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.923
_cell_length_b   9.923
_cell_length_c   10.732
_cell_angle_alpha   58.022
_cell_angle_beta   58.022
_cell_angle_gamma   47.819
_symmetry_Int_Tables_number   1
_cell_volume   638.340
_cell_formula_units_Z   2
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  0.251  0.158  0.533  1.0
  Ca  Ca1  1  0.842  0.749  0.967  1.0
  Ca  Ca2  1  0.158  0.251  0.033  1.0
  Ca  Ca3  1  0.641  0.359  0.250  1.0
  Ca  Ca4  1  0.749  0.842  0.467  1.0
  Ca  Ca5  1  0.359  0.641  0.750  1.0
  Si  Si6  1  0.087  0.534  0.666  1.0
  Si  Si7  1  0.534  0.087  0.166  1.0
  Si  Si8  1  0.250  0.492  0.136  1.0
  Si  Si9  1  0.492  0.250  0.636  1.0
  Si  Si10  1  0.466  0.913  0.834  1.0
  Si  Si11  1  0.750  0.508  0.864  1.0
  Si  Si12  1  0.508  0.750  0.364  1.0
  Si  Si13  1  0.913  0.466  0.334  1.0
  Sb  Sb14  1  0.219  0.781  0.250  1.0
  Sb  Sb15  1  0.781  0.219  0.750  1.0
  Sb  Sb16  1  0.000  0.000  0.000  1.0
  Sb  Sb17  1  0.000  0.000  0.500  1.0
  O  O18  1  0.330  0.849  0.502  1.0
  O  O19  1  0.890  0.960  0.746  1.0
  O  O20  1  0.604  0.515  0.832  1.0
  O  O21  1  0.960  0.890  0.246  1.0
  O  O22  1  0.950  0.272  0.479  1.0
  O  O23  1  0.483  0.084  0.806  1.0
  O  O24  1  0.515  0.604  0.332  1.0
  O  O25  1  0.728  0.050  0.021  1.0
  O  O26  1  0.517  0.916  0.194  1.0
  O  O27  1  0.710  0.649  0.402  1.0
  O  O28  1  0.110  0.040  0.254  1.0
  O  O29  1  0.050  0.728  0.521  1.0
  O  O30  1  0.916  0.517  0.694  1.0
  O  O31  1  0.849  0.330  0.002  1.0
  O  O32  1  0.649  0.710  0.902  1.0
  O  O33  1  0.272  0.950  0.979  1.0
  O  O34  1  0.473  0.922  0.677  1.0
  O  O35  1  0.290  0.351  0.598  1.0
  O  O36  1  0.078  0.527  0.823  1.0
  O  O37  1  0.351  0.290  0.098  1.0
  O  O38  1  0.084  0.483  0.306  1.0
  O  O39  1  0.040  0.110  0.754  1.0
  O  O40  1  0.922  0.473  0.177  1.0
  O  O41  1  0.396  0.485  0.168  1.0
  O  O42  1  0.527  0.078  0.323  1.0
  O  O43  1  0.485  0.396  0.668  1.0
  O  O44  1  0.151  0.670  0.998  1.0
  O  O45  1  0.670  0.151  0.498  1.0
[/CIF]
.