The material structure described by Sr4Ca(SO4)4 crystallizes in the monoclinic Pm space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(8), two equivalent O(10), two equivalent O(2), and four equivalent O(12) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(7), two equivalent O(1), and four equivalent O(11) atoms. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(6), two equivalent O(12), two equivalent O(4), and four equivalent O(10) atoms. In the fourth Sr site, Sr(4) is bonded to one O(5), two equivalent O(3), and four equivalent O(9) atoms to form distorted SrO7 hexagonal pyramids that share corners with two equivalent Sr(4)O7 hexagonal pyramids,  a cornercorner with one S(4)O4 tetrahedra, corners with two equivalent S(1)O4 tetrahedra, edges with two equivalent Sr(4)O7 hexagonal pyramids, and edges with two equivalent S(1)O4 tetrahedra. Ca(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(11) and two equivalent O(9) atoms. There are four inequivalent S sites. In the first S site, S(1) is bonded to one O(3), one O(8), and two equivalent O(9) atoms to form SO4 tetrahedra that share corners with two equivalent Sr(4)O7 hexagonal pyramids and edges with two equivalent Sr(4)O7 hexagonal pyramids. In the second S site, S(2) is bonded in a tetrahedral geometry to one O(4), one O(7), and two equivalent O(10) atoms. In the third S site, S(3) is bonded in a tetrahedral geometry to one O(1), one O(6), and two equivalent O(11) atoms. In the fourth S site, S(4) is bonded to one O(2), one O(5), and two equivalent O(12) atoms to form SO4 tetrahedra that share  a cornercorner with one Sr(4)O7 hexagonal pyramid. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Sr(2) and one S(3) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one S(4) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Sr(4) and one S(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Sr(3) and one S(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Sr(4) and one S(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Sr(3) and one S(3) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Sr(2) and one S(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Sr(1) and one S(1) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to two equivalent Sr(4), one Ca(1), and one S(1) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Sr(1), two equivalent Sr(3), and one S(2) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to two equivalent Sr(2), one Ca(1), and one S(3) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one Sr(3), two equivalent Sr(1), and one S(4) atom. is represented by the CIF file [CIF]
data_Sr4Ca(SO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.166
_cell_length_b   4.794
_cell_length_c   16.621
_cell_angle_alpha   80.408
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   405.930
_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
  Sr  Sr0  1  0.250  0.247  0.586  1.0
  Sr  Sr1  1  0.250  0.346  0.163  1.0
  Sr  Sr2  1  0.750  0.760  0.413  1.0
  Sr  Sr3  1  0.750  0.603  0.851  1.0
  Ca  Ca4  1  0.250  0.965  0.998  1.0
  S  S5  1  0.250  0.190  0.815  1.0
  S  S6  1  0.250  0.224  0.388  1.0
  S  S7  1  0.750  0.798  0.176  1.0
  S  S8  1  0.750  0.786  0.614  1.0
  O  O9  1  0.750  0.485  0.182  1.0
  O  O10  1  0.750  0.098  0.614  1.0
  O  O11  1  0.250  0.501  0.810  1.0
  O  O12  1  0.250  0.916  0.384  1.0
  O  O13  1  0.750  0.627  0.698  1.0
  O  O14  1  0.750  0.882  0.257  1.0
  O  O15  1  0.250  0.398  0.307  1.0
  O  O16  1  0.250  0.102  0.735  1.0
  O  O17  1  0.016  0.073  0.865  1.0
  O  O18  1  0.485  0.286  0.436  1.0
  O  O19  1  0.510  0.911  0.130  1.0
  O  O20  1  0.984  0.717  0.567  1.0
  O  O21  1  0.990  0.911  0.130  1.0
  O  O22  1  0.516  0.717  0.567  1.0
  O  O23  1  0.484  0.073  0.865  1.0
  O  O24  1  0.015  0.286  0.436  1.0
[/CIF]
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The material structure described by Sr4Ca(SO4)4 crystallizes in the monoclinic Pm space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(8), two equivalent O(10), two equivalent O(2), and four equivalent O(12) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(7), two equivalent O(1), and four equivalent O(11) atoms. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(6), two equivalent O(12), two equivalent O(4), and four equivalent O(10) atoms. In the fourth Sr site, Sr(4) is bonded to one O(5), two equivalent O(3), and four equivalent O(9) atoms to form distorted SrO7 hexagonal pyramids that share corners with two equivalent Sr(4)O7 hexagonal pyramids,  a cornercorner with one S(4)O4 tetrahedra, corners with two equivalent S(1)O4 tetrahedra, edges with two equivalent Sr(4)O7 hexagonal pyramids, and edges with two equivalent S(1)O4 tetrahedra. Ca(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(11) and two equivalent O(9) atoms. There are four inequivalent S sites. In the first S site, S(1) is bonded to one O(3), one O(8), and two equivalent O(9) atoms to form SO4 tetrahedra that share corners with two equivalent Sr(4)O7 hexagonal pyramids and edges with two equivalent Sr(4)O7 hexagonal pyramids. In the second S site, S(2) is bonded in a tetrahedral geometry to one O(4), one O(7), and two equivalent O(10) atoms. In the third S site, S(3) is bonded in a tetrahedral geometry to one O(1), one O(6), and two equivalent O(11) atoms. In the fourth S site, S(4) is bonded to one O(2), one O(5), and two equivalent O(12) atoms to form SO4 tetrahedra that share  a cornercorner with one Sr(4)O7 hexagonal pyramid. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Sr(2) and one S(3) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one S(4) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Sr(4) and one S(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Sr(3) and one S(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Sr(4) and one S(4) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Sr(3) and one S(3) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Sr(2) and one S(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Sr(1) and one S(1) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to two equivalent Sr(4), one Ca(1), and one S(1) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Sr(1), two equivalent Sr(3), and one S(2) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to two equivalent Sr(2), one Ca(1), and one S(3) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one Sr(3), two equivalent Sr(1), and one S(4) atom. is represented by the CIF file [CIF]
data_Sr4Ca(SO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.166
_cell_length_b   4.794
_cell_length_c   16.621
_cell_angle_alpha   80.408
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   405.930
_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
  Sr  Sr0  1  0.250  0.247  0.586  1.0
  Sr  Sr1  1  0.250  0.346  0.163  1.0
  Sr  Sr2  1  0.750  0.760  0.413  1.0
  Sr  Sr3  1  0.750  0.603  0.851  1.0
  Ca  Ca4  1  0.250  0.965  0.998  1.0
  S  S5  1  0.250  0.190  0.815  1.0
  S  S6  1  0.250  0.224  0.388  1.0
  S  S7  1  0.750  0.798  0.176  1.0
  S  S8  1  0.750  0.786  0.614  1.0
  O  O9  1  0.750  0.485  0.182  1.0
  O  O10  1  0.750  0.098  0.614  1.0
  O  O11  1  0.250  0.501  0.810  1.0
  O  O12  1  0.250  0.916  0.384  1.0
  O  O13  1  0.750  0.627  0.698  1.0
  O  O14  1  0.750  0.882  0.257  1.0
  O  O15  1  0.250  0.398  0.307  1.0
  O  O16  1  0.250  0.102  0.735  1.0
  O  O17  1  0.016  0.073  0.865  1.0
  O  O18  1  0.485  0.286  0.436  1.0
  O  O19  1  0.510  0.911  0.130  1.0
  O  O20  1  0.984  0.717  0.567  1.0
  O  O21  1  0.990  0.911  0.130  1.0
  O  O22  1  0.516  0.717  0.567  1.0
  O  O23  1  0.484  0.073  0.865  1.0
  O  O24  1  0.015  0.286  0.436  1.0
[/CIF]
.