The material described by SrCa7Mn8O20 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic Cm space group. Sr(1) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(3), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(2), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. In the third Ca site, Ca(3) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(4), one O(6), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to two equivalent O(10), two equivalent O(11), two equivalent O(2), and two equivalent O(9) atoms. In the fifth Ca site, Ca(5) is bonded in a 10-coordinate geometry to one O(1), one O(4), two equivalent O(10), two equivalent O(11), two equivalent O(3), and two equivalent O(9) atoms. There are six inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted trigonal planar geometry to one O(1) and two equivalent O(5) atoms. In the second Mn site, Mn(2) is bonded to one O(1), two equivalent O(6), and two equivalent O(9) atoms to form corner-sharing MnO5 square pyramids. The corner-sharing octahedral tilt angles range from 8-19°. In the third Mn site, Mn(3) is bonded to one O(10), one O(2), one O(3), one O(5), and one O(7) atom to form MnO5 trigonal bipyramids that share corners with two equivalent Mn(4)O6 octahedra and corners with two equivalent Mn(5)O5 square pyramids. The corner-sharing octahedral tilt angles range from 15-21°. In the fourth Mn site, Mn(4) is bonded to one O(11), one O(2), one O(3), one O(6), one O(8), and one O(9) atom to form corner-sharing MnO6 octahedra. In the fifth Mn site, Mn(5) is bonded to one O(4), two equivalent O(10), and two equivalent O(7) atoms to form corner-sharing MnO5 square pyramids. In the sixth Mn site, Mn(6) is bonded to one O(4), two equivalent O(11), and two equivalent O(8) atoms to form MnO5 square pyramids that share corners with four equivalent Mn(4)O6 octahedra and  a cornercorner with one Mn(5)O5 square pyramid. The corner-sharing octahedral tilt angles range from 3-11°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(5), two equivalent Ca(3), one Mn(1), and one Mn(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Sr(1), one Ca(2), one Ca(4), one Mn(3), and one Mn(4) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(5), two equivalent Ca(3), one Mn(3), and one Mn(4) atom. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(5), two equivalent Ca(3), one Mn(5), and one Mn(6) atom to form distorted OCa4Mn2 octahedra that share faces with two equivalent O(11)Ca4Mn2 octahedra and faces with two equivalent O(8)SrCa3Mn2 octahedra. In the fifth O site, O(5) is bonded to one Sr(1), one Ca(2), one Mn(1), and one Mn(3) atom to form distorted OSrCaMn2 tetrahedra that share  a cornercorner with one O(11)Ca4Mn2 octahedra, corners with three equivalent O(8)SrCa3Mn2 octahedra, and  an edgeedge with one O(5)SrCaMn2 tetrahedra. The corner-sharing octahedral tilt angles range from 7-63°. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(2), and one Mn(4) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(3), and one Mn(5) atom. In the eighth O site, O(8) is bonded to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(4), and one Mn(6) atom to form distorted OSrCa3Mn2 octahedra that share corners with two equivalent O(11)Ca4Mn2 octahedra, corners with three equivalent O(5)SrCaMn2 tetrahedra,  a faceface with one O(11)Ca4Mn2 octahedra,  a faceface with one O(4)Ca4Mn2 octahedra, and  a faceface with one O(8)SrCa3Mn2 octahedra. The corner-sharing octahedral tilt angles range from 6-8°. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), one Ca(5), one Mn(2), and one Mn(4) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Ca(2), one Ca(4), one Ca(5), one Mn(3), and one Mn(5) atom. In the eleventh O site, O(11) is bonded to one Ca(2), one Ca(3), one Ca(4), one Ca(5), one Mn(4), and one Mn(6) atom to form distorted OCa4Mn2 octahedra that share corners with two equivalent O(8)SrCa3Mn2 octahedra,  a cornercorner with one O(5)SrCaMn2 tetrahedra,  a faceface with one O(11)Ca4Mn2 octahedra,  a faceface with one O(4)Ca4Mn2 octahedra, and  a faceface with one O(8)SrCa3Mn2 octahedra. The corner-sharing octahedral tilt angles range from 6-8°. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrCa7Mn8O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.822
_cell_length_b   7.822
_cell_length_c   7.683
_cell_angle_alpha   88.191
_cell_angle_beta   88.191
_cell_angle_gamma   90.172
_symmetry_Int_Tables_number   1
_cell_volume   469.578
_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  0.246  0.246  0.244  1.0
  Ca  Ca1  1  0.268  0.268  0.700  1.0
  Ca  Ca2  1  0.257  0.736  0.260  1.0
  Ca  Ca3  1  0.247  0.730  0.716  1.0
  Ca  Ca4  1  0.736  0.257  0.260  1.0
  Ca  Ca5  1  0.730  0.247  0.716  1.0
  Ca  Ca6  1  0.743  0.743  0.271  1.0
  Ca  Ca7  1  0.733  0.733  0.725  1.0
  Mn  Mn8  1  0.000  0.000  0.996  1.0
  Mn  Mn9  1  0.001  0.001  0.522  1.0
  Mn  Mn10  1  0.997  0.487  0.002  1.0
  Mn  Mn11  1  0.000  0.509  0.492  1.0
  Mn  Mn12  1  0.487  0.997  0.002  1.0
  Mn  Mn13  1  0.509  0.000  0.492  1.0
  Mn  Mn14  1  0.506  0.506  0.991  1.0
  Mn  Mn15  1  0.504  0.504  0.497  1.0
  O  O16  1  0.933  0.933  0.780  1.0
  O  O17  1  0.016  0.538  0.240  1.0
  O  O18  1  0.996  0.530  0.751  1.0
  O  O19  1  0.538  0.016  0.240  1.0
  O  O20  1  0.530  0.996  0.751  1.0
  O  O21  1  0.511  0.511  0.744  1.0
  O  O22  1  0.226  0.968  0.065  1.0
  O  O23  1  0.252  0.004  0.526  1.0
  O  O24  1  0.255  0.510  0.002  1.0
  O  O25  1  0.260  0.503  0.489  1.0
  O  O26  1  0.763  0.010  0.466  1.0
  O  O27  1  0.749  0.518  0.035  1.0
  O  O28  1  0.746  0.501  0.470  1.0
  O  O29  1  0.968  0.226  0.065  1.0
  O  O30  1  0.004  0.252  0.526  1.0
  O  O31  1  0.010  0.763  0.466  1.0
  O  O32  1  0.510  0.255  0.002  1.0
  O  O33  1  0.503  0.260  0.489  1.0
  O  O34  1  0.518  0.749  0.035  1.0
  O  O35  1  0.501  0.746  0.470  1.0
[/CIF]
.
The material described by SrCa7Mn8O20 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic Cm space group. Sr(1) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(3), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(2), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. In the third Ca site, Ca(3) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(4), one O(6), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to two equivalent O(10), two equivalent O(11), two equivalent O(2), and two equivalent O(9) atoms. In the fifth Ca site, Ca(5) is bonded in a 10-coordinate geometry to one O(1), one O(4), two equivalent O(10), two equivalent O(11), two equivalent O(3), and two equivalent O(9) atoms. There are six inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted trigonal planar geometry to one O(1) and two equivalent O(5) atoms. In the second Mn site, Mn(2) is bonded to one O(1), two equivalent O(6), and two equivalent O(9) atoms to form corner-sharing MnO5 square pyramids. The corner-sharing octahedral tilt angles range from 8-19°. In the third Mn site, Mn(3) is bonded to one O(10), one O(2), one O(3), one O(5), and one O(7) atom to form MnO5 trigonal bipyramids that share corners with two equivalent Mn(4)O6 octahedra and corners with two equivalent Mn(5)O5 square pyramids. The corner-sharing octahedral tilt angles range from 15-21°. In the fourth Mn site, Mn(4) is bonded to one O(11), one O(2), one O(3), one O(6), one O(8), and one O(9) atom to form corner-sharing MnO6 octahedra. In the fifth Mn site, Mn(5) is bonded to one O(4), two equivalent O(10), and two equivalent O(7) atoms to form corner-sharing MnO5 square pyramids. In the sixth Mn site, Mn(6) is bonded to one O(4), two equivalent O(11), and two equivalent O(8) atoms to form MnO5 square pyramids that share corners with four equivalent Mn(4)O6 octahedra and  a cornercorner with one Mn(5)O5 square pyramid. The corner-sharing octahedral tilt angles range from 3-11°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(5), two equivalent Ca(3), one Mn(1), and one Mn(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Sr(1), one Ca(2), one Ca(4), one Mn(3), and one Mn(4) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(5), two equivalent Ca(3), one Mn(3), and one Mn(4) atom. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(5), two equivalent Ca(3), one Mn(5), and one Mn(6) atom to form distorted OCa4Mn2 octahedra that share faces with two equivalent O(11)Ca4Mn2 octahedra and faces with two equivalent O(8)SrCa3Mn2 octahedra. In the fifth O site, O(5) is bonded to one Sr(1), one Ca(2), one Mn(1), and one Mn(3) atom to form distorted OSrCaMn2 tetrahedra that share  a cornercorner with one O(11)Ca4Mn2 octahedra, corners with three equivalent O(8)SrCa3Mn2 octahedra, and  an edgeedge with one O(5)SrCaMn2 tetrahedra. The corner-sharing octahedral tilt angles range from 7-63°. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(2), and one Mn(4) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(3), and one Mn(5) atom. In the eighth O site, O(8) is bonded to one Sr(1), one Ca(1), one Ca(2), one Ca(3), one Mn(4), and one Mn(6) atom to form distorted OSrCa3Mn2 octahedra that share corners with two equivalent O(11)Ca4Mn2 octahedra, corners with three equivalent O(5)SrCaMn2 tetrahedra,  a faceface with one O(11)Ca4Mn2 octahedra,  a faceface with one O(4)Ca4Mn2 octahedra, and  a faceface with one O(8)SrCa3Mn2 octahedra. The corner-sharing octahedral tilt angles range from 6-8°. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), one Ca(5), one Mn(2), and one Mn(4) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Ca(2), one Ca(4), one Ca(5), one Mn(3), and one Mn(5) atom. In the eleventh O site, O(11) is bonded to one Ca(2), one Ca(3), one Ca(4), one Ca(5), one Mn(4), and one Mn(6) atom to form distorted OCa4Mn2 octahedra that share corners with two equivalent O(8)SrCa3Mn2 octahedra,  a cornercorner with one O(5)SrCaMn2 tetrahedra,  a faceface with one O(11)Ca4Mn2 octahedra,  a faceface with one O(4)Ca4Mn2 octahedra, and  a faceface with one O(8)SrCa3Mn2 octahedra. The corner-sharing octahedral tilt angles range from 6-8°. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrCa7Mn8O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.822
_cell_length_b   7.822
_cell_length_c   7.683
_cell_angle_alpha   88.191
_cell_angle_beta   88.191
_cell_angle_gamma   90.172
_symmetry_Int_Tables_number   1
_cell_volume   469.578
_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  0.246  0.246  0.244  1.0
  Ca  Ca1  1  0.268  0.268  0.700  1.0
  Ca  Ca2  1  0.257  0.736  0.260  1.0
  Ca  Ca3  1  0.247  0.730  0.716  1.0
  Ca  Ca4  1  0.736  0.257  0.260  1.0
  Ca  Ca5  1  0.730  0.247  0.716  1.0
  Ca  Ca6  1  0.743  0.743  0.271  1.0
  Ca  Ca7  1  0.733  0.733  0.725  1.0
  Mn  Mn8  1  0.000  0.000  0.996  1.0
  Mn  Mn9  1  0.001  0.001  0.522  1.0
  Mn  Mn10  1  0.997  0.487  0.002  1.0
  Mn  Mn11  1  0.000  0.509  0.492  1.0
  Mn  Mn12  1  0.487  0.997  0.002  1.0
  Mn  Mn13  1  0.509  0.000  0.492  1.0
  Mn  Mn14  1  0.506  0.506  0.991  1.0
  Mn  Mn15  1  0.504  0.504  0.497  1.0
  O  O16  1  0.933  0.933  0.780  1.0
  O  O17  1  0.016  0.538  0.240  1.0
  O  O18  1  0.996  0.530  0.751  1.0
  O  O19  1  0.538  0.016  0.240  1.0
  O  O20  1  0.530  0.996  0.751  1.0
  O  O21  1  0.511  0.511  0.744  1.0
  O  O22  1  0.226  0.968  0.065  1.0
  O  O23  1  0.252  0.004  0.526  1.0
  O  O24  1  0.255  0.510  0.002  1.0
  O  O25  1  0.260  0.503  0.489  1.0
  O  O26  1  0.763  0.010  0.466  1.0
  O  O27  1  0.749  0.518  0.035  1.0
  O  O28  1  0.746  0.501  0.470  1.0
  O  O29  1  0.968  0.226  0.065  1.0
  O  O30  1  0.004  0.252  0.526  1.0
  O  O31  1  0.010  0.763  0.466  1.0
  O  O32  1  0.510  0.255  0.002  1.0
  O  O33  1  0.503  0.260  0.489  1.0
  O  O34  1  0.518  0.749  0.035  1.0
  O  O35  1  0.501  0.746  0.470  1.0
[/CIF]
.