The crystal structure described by Sr3Ca5Mn8O21 is Orthorhombic Perovskite-derived structured and crystallizes in the triclinic P1 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 10-coordinate geometry to one O(10), one O(14), one O(15), one O(18), one O(19), one O(2), one O(4), one O(7), one O(8), and one O(9) atom. In the second Sr site, Sr(2) is bonded in a 10-coordinate geometry to one O(10), one O(14), one O(15), one O(18), one O(19), one O(3), one O(5), one O(6), one O(8), and one O(9) atom. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one O(11), one O(12), one O(13), one O(14), one O(15), one O(18), one O(19), one O(2), and one O(4) atom. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(10), one O(16), one O(17), one O(2), one O(20), one O(21), one O(7), one O(8), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(10), one O(17), one O(21), one O(3), one O(5), one O(6), one O(8), and one O(9) atom. In the third Ca site, Ca(3) is bonded in a 4-coordinate geometry to one O(1), one O(13), one O(14), one O(15), one O(18), one O(19), and one O(3) atom. In the fourth Ca site, Ca(4) is bonded in a 9-coordinate geometry to one O(11), one O(12), one O(13), one O(16), one O(17), one O(2), one O(20), one O(21), and one O(4) atom. In the fifth Ca site, Ca(5) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(13), one O(20), one O(3), one O(5), and one O(6) atom. There are eight inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(14), one O(16), and one O(7) atom. In the second Mn site, Mn(2) is bonded to one O(1), one O(11), one O(15), one O(17), and one O(8) atom to form corner-sharing MnO5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-25°. In the third Mn site, Mn(3) is bonded to one O(12), one O(14), one O(16), one O(2), one O(3), and one O(9) atom to form MnO6 octahedra that share corners with two equivalent Mn(4)O6 octahedra and corners with two equivalent Mn(7)O5 square pyramids. The corner-sharing octahedral tilt angles range from 12-13°. In the fourth Mn site, Mn(4) is bonded to one O(10), one O(13), one O(15), one O(17), one O(2), and one O(3) atom to form MnO6 octahedra that share corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(8)O5 square pyramids, and corners with two equivalent Mn(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 12-13°. In the fifth Mn site, Mn(5) is bonded to one O(18), one O(20), one O(4), one O(5), and one O(7) atom to form MnO5 square pyramids that share corners with two equivalent Mn(6)O6 octahedra and corners with two equivalent Mn(7)O5 square pyramids. The corner-sharing octahedral tilt angles range from 18-25°. In the sixth Mn site, Mn(6) is bonded to one O(11), one O(19), one O(21), one O(4), one O(5), and one O(8) atom to form corner-sharing MnO6 octahedra. In the seventh Mn site, Mn(7) is bonded to one O(12), one O(18), one O(20), one O(6), and one O(9) atom to form MnO5 square pyramids that share corners with two equivalent Mn(3)O6 octahedra,  a cornercorner with one Mn(8)O5 square pyramid, and corners with two equivalent Mn(5)O5 square pyramids. The corner-sharing octahedral tilt angles range from 11-18°. In the eighth Mn site, Mn(8) is bonded to one O(10), one O(13), one O(19), one O(21), and one O(6) atom to form MnO5 square pyramids that share corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, and  a cornercorner with one Mn(7)O5 square pyramid. The corner-sharing octahedral tilt angles range from 10-29°. There are twenty-one inequivalent O sites. In the first O site, O(1) is bonded to one Ca(3), one Ca(5), one Mn(1), and one Mn(2) atom to form distorted edge-sharing OCa2Mn2 tetrahedra. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(3), one Ca(1), one Ca(4), one Mn(3), and one Mn(4) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Sr(2), one Ca(2), one Ca(3), one Ca(5), one Mn(3), and one Mn(4) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Ca(4), one Mn(5), and one Mn(6) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Sr(2), one Ca(2), one Ca(5), one Mn(5), and one Mn(6) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(2), one Ca(2), one Ca(5), one Mn(7), and one Mn(8) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Mn(1), and one Mn(5) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one Ca(2), one Mn(2), and one Mn(6) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one Ca(2), one Mn(3), and one Mn(7) atom. In the tenth O site, O(10) is bonded to one Sr(1), one Sr(2), one Ca(1), one Ca(2), one Mn(4), and one Mn(8) atom to form distorted OSr2Ca2Mn2 octahedra that share corners with two equivalent O(14)Sr3CaMn2 octahedra and  a faceface with one O(21)Ca3Mn2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 56-57°. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(3), one Ca(4), one Ca(5), one Mn(2), and one Mn(6) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Sr(3), one Ca(4), one Mn(3), and one Mn(7) atom. In the thirteenth O site, O(13) is bonded in a 6-coordinate geometry to one Sr(3), one Ca(3), one Ca(4), one Ca(5), one Mn(4), and one Mn(8) atom. In the fourteenth O site, O(14) is bonded to one Sr(1), one Sr(2), one Sr(3), one Ca(3), one Mn(1), and one Mn(3) atom to form distorted OSr3CaMn2 octahedra that share corners with two equivalent O(10)Sr2Ca2Mn2 octahedra and  an edgeedge with one O(1)Ca2Mn2 tetrahedra. The corner-sharing octahedral tilt angles range from 56-57°. In the fifteenth O site, O(15) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Ca(3), one Mn(2), and one Mn(4) atom. In the sixteenth O site, O(16) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(4), one Mn(1), and one Mn(3) atom. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(4), one Mn(2), and one Mn(4) atom. In the eighteenth O site, O(18) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Ca(3), one Mn(5), and one Mn(7) atom. In the nineteenth O site, O(19) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Ca(3), one Mn(6), and one Mn(8) atom. In the twentieth O site, O(20) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(4), one Ca(5), one Mn(5), and one Mn(7) atom. In the twenty-first O site, O(21) is bonded to one Ca(1), one Ca(2), one Ca(4), one Mn(6), and one Mn(8) atom to form distorted face-sharing OCa3Mn2 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr3Ca5Mn8O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.848
_cell_length_b   7.770
_cell_length_c   7.745
_cell_angle_alpha   89.968
_cell_angle_beta   87.873
_cell_angle_gamma   89.646
_symmetry_Int_Tables_number   1
_cell_volume   471.992
_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  0.252  0.247  0.248  1.0
  Sr  Sr1  1  0.257  0.265  0.743  1.0
  Sr  Sr2  1  0.764  0.257  0.265  1.0
  Ca  Ca3  1  0.238  0.736  0.238  1.0
  Ca  Ca4  1  0.262  0.741  0.692  1.0
  Ca  Ca5  1  0.752  0.249  0.748  1.0
  Ca  Ca6  1  0.743  0.739  0.260  1.0
  Ca  Ca7  1  0.747  0.741  0.737  1.0
  Mn  Mn8  1  0.015  0.992  0.979  1.0
  Mn  Mn9  1  0.997  0.996  0.519  1.0
  Mn  Mn10  1  0.996  0.508  0.008  1.0
  Mn  Mn11  1  0.002  0.504  0.500  1.0
  Mn  Mn12  1  0.490  0.993  0.997  1.0
  Mn  Mn13  1  0.509  0.996  0.487  1.0
  Mn  Mn14  1  0.504  0.508  0.986  1.0
  Mn  Mn15  1  0.506  0.503  0.506  1.0
  O  O16  1  0.906  0.985  0.770  1.0
  O  O17  1  0.012  0.480  0.254  1.0
  O  O18  1  1.000  0.532  0.756  1.0
  O  O19  1  0.530  0.039  0.237  1.0
  O  O20  1  0.511  0.956  0.745  1.0
  O  O21  1  0.499  0.549  0.747  1.0
  O  O22  1  0.236  0.984  0.059  1.0
  O  O23  1  0.248  0.016  0.514  1.0
  O  O24  1  0.260  0.512  0.020  1.0
  O  O25  1  0.260  0.483  0.492  1.0
  O  O26  1  0.762  0.971  0.454  1.0
  O  O27  1  0.741  0.489  0.031  1.0
  O  O28  1  0.749  0.528  0.487  1.0
  O  O29  1  0.990  0.237  0.000  1.0
  O  O30  1  0.980  0.249  0.519  1.0
  O  O31  1  0.966  0.766  0.055  1.0
  O  O32  1  0.035  0.752  0.478  1.0
  O  O33  1  0.504  0.250  0.964  1.0
  O  O34  1  0.528  0.255  0.516  1.0
  O  O35  1  0.526  0.748  0.047  1.0
  O  O36  1  0.476  0.743  0.442  1.0
[/CIF]
.
The crystal structure described by Sr3Ca5Mn8O21 is Orthorhombic Perovskite-derived structured and crystallizes in the triclinic P1 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 10-coordinate geometry to one O(10), one O(14), one O(15), one O(18), one O(19), one O(2), one O(4), one O(7), one O(8), and one O(9) atom. In the second Sr site, Sr(2) is bonded in a 10-coordinate geometry to one O(10), one O(14), one O(15), one O(18), one O(19), one O(3), one O(5), one O(6), one O(8), and one O(9) atom. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one O(11), one O(12), one O(13), one O(14), one O(15), one O(18), one O(19), one O(2), and one O(4) atom. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(10), one O(16), one O(17), one O(2), one O(20), one O(21), one O(7), one O(8), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(10), one O(17), one O(21), one O(3), one O(5), one O(6), one O(8), and one O(9) atom. In the third Ca site, Ca(3) is bonded in a 4-coordinate geometry to one O(1), one O(13), one O(14), one O(15), one O(18), one O(19), and one O(3) atom. In the fourth Ca site, Ca(4) is bonded in a 9-coordinate geometry to one O(11), one O(12), one O(13), one O(16), one O(17), one O(2), one O(20), one O(21), and one O(4) atom. In the fifth Ca site, Ca(5) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(13), one O(20), one O(3), one O(5), and one O(6) atom. There are eight inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(14), one O(16), and one O(7) atom. In the second Mn site, Mn(2) is bonded to one O(1), one O(11), one O(15), one O(17), and one O(8) atom to form corner-sharing MnO5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-25°. In the third Mn site, Mn(3) is bonded to one O(12), one O(14), one O(16), one O(2), one O(3), and one O(9) atom to form MnO6 octahedra that share corners with two equivalent Mn(4)O6 octahedra and corners with two equivalent Mn(7)O5 square pyramids. The corner-sharing octahedral tilt angles range from 12-13°. In the fourth Mn site, Mn(4) is bonded to one O(10), one O(13), one O(15), one O(17), one O(2), and one O(3) atom to form MnO6 octahedra that share corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(8)O5 square pyramids, and corners with two equivalent Mn(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 12-13°. In the fifth Mn site, Mn(5) is bonded to one O(18), one O(20), one O(4), one O(5), and one O(7) atom to form MnO5 square pyramids that share corners with two equivalent Mn(6)O6 octahedra and corners with two equivalent Mn(7)O5 square pyramids. The corner-sharing octahedral tilt angles range from 18-25°. In the sixth Mn site, Mn(6) is bonded to one O(11), one O(19), one O(21), one O(4), one O(5), and one O(8) atom to form corner-sharing MnO6 octahedra. In the seventh Mn site, Mn(7) is bonded to one O(12), one O(18), one O(20), one O(6), and one O(9) atom to form MnO5 square pyramids that share corners with two equivalent Mn(3)O6 octahedra,  a cornercorner with one Mn(8)O5 square pyramid, and corners with two equivalent Mn(5)O5 square pyramids. The corner-sharing octahedral tilt angles range from 11-18°. In the eighth Mn site, Mn(8) is bonded to one O(10), one O(13), one O(19), one O(21), and one O(6) atom to form MnO5 square pyramids that share corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, and  a cornercorner with one Mn(7)O5 square pyramid. The corner-sharing octahedral tilt angles range from 10-29°. There are twenty-one inequivalent O sites. In the first O site, O(1) is bonded to one Ca(3), one Ca(5), one Mn(1), and one Mn(2) atom to form distorted edge-sharing OCa2Mn2 tetrahedra. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(3), one Ca(1), one Ca(4), one Mn(3), and one Mn(4) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Sr(2), one Ca(2), one Ca(3), one Ca(5), one Mn(3), and one Mn(4) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Ca(4), one Mn(5), and one Mn(6) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Sr(2), one Ca(2), one Ca(5), one Mn(5), and one Mn(6) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(2), one Ca(2), one Ca(5), one Mn(7), and one Mn(8) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Mn(1), and one Mn(5) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one Ca(2), one Mn(2), and one Mn(6) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one Ca(2), one Mn(3), and one Mn(7) atom. In the tenth O site, O(10) is bonded to one Sr(1), one Sr(2), one Ca(1), one Ca(2), one Mn(4), and one Mn(8) atom to form distorted OSr2Ca2Mn2 octahedra that share corners with two equivalent O(14)Sr3CaMn2 octahedra and  a faceface with one O(21)Ca3Mn2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 56-57°. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(3), one Ca(4), one Ca(5), one Mn(2), and one Mn(6) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Sr(3), one Ca(4), one Mn(3), and one Mn(7) atom. In the thirteenth O site, O(13) is bonded in a 6-coordinate geometry to one Sr(3), one Ca(3), one Ca(4), one Ca(5), one Mn(4), and one Mn(8) atom. In the fourteenth O site, O(14) is bonded to one Sr(1), one Sr(2), one Sr(3), one Ca(3), one Mn(1), and one Mn(3) atom to form distorted OSr3CaMn2 octahedra that share corners with two equivalent O(10)Sr2Ca2Mn2 octahedra and  an edgeedge with one O(1)Ca2Mn2 tetrahedra. The corner-sharing octahedral tilt angles range from 56-57°. In the fifteenth O site, O(15) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Ca(3), one Mn(2), and one Mn(4) atom. In the sixteenth O site, O(16) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(4), one Mn(1), and one Mn(3) atom. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(4), one Mn(2), and one Mn(4) atom. In the eighteenth O site, O(18) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Ca(3), one Mn(5), and one Mn(7) atom. In the nineteenth O site, O(19) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Ca(3), one Mn(6), and one Mn(8) atom. In the twentieth O site, O(20) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(4), one Ca(5), one Mn(5), and one Mn(7) atom. In the twenty-first O site, O(21) is bonded to one Ca(1), one Ca(2), one Ca(4), one Mn(6), and one Mn(8) atom to form distorted face-sharing OCa3Mn2 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr3Ca5Mn8O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.848
_cell_length_b   7.770
_cell_length_c   7.745
_cell_angle_alpha   89.968
_cell_angle_beta   87.873
_cell_angle_gamma   89.646
_symmetry_Int_Tables_number   1
_cell_volume   471.992
_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  0.252  0.247  0.248  1.0
  Sr  Sr1  1  0.257  0.265  0.743  1.0
  Sr  Sr2  1  0.764  0.257  0.265  1.0
  Ca  Ca3  1  0.238  0.736  0.238  1.0
  Ca  Ca4  1  0.262  0.741  0.692  1.0
  Ca  Ca5  1  0.752  0.249  0.748  1.0
  Ca  Ca6  1  0.743  0.739  0.260  1.0
  Ca  Ca7  1  0.747  0.741  0.737  1.0
  Mn  Mn8  1  0.015  0.992  0.979  1.0
  Mn  Mn9  1  0.997  0.996  0.519  1.0
  Mn  Mn10  1  0.996  0.508  0.008  1.0
  Mn  Mn11  1  0.002  0.504  0.500  1.0
  Mn  Mn12  1  0.490  0.993  0.997  1.0
  Mn  Mn13  1  0.509  0.996  0.487  1.0
  Mn  Mn14  1  0.504  0.508  0.986  1.0
  Mn  Mn15  1  0.506  0.503  0.506  1.0
  O  O16  1  0.906  0.985  0.770  1.0
  O  O17  1  0.012  0.480  0.254  1.0
  O  O18  1  1.000  0.532  0.756  1.0
  O  O19  1  0.530  0.039  0.237  1.0
  O  O20  1  0.511  0.956  0.745  1.0
  O  O21  1  0.499  0.549  0.747  1.0
  O  O22  1  0.236  0.984  0.059  1.0
  O  O23  1  0.248  0.016  0.514  1.0
  O  O24  1  0.260  0.512  0.020  1.0
  O  O25  1  0.260  0.483  0.492  1.0
  O  O26  1  0.762  0.971  0.454  1.0
  O  O27  1  0.741  0.489  0.031  1.0
  O  O28  1  0.749  0.528  0.487  1.0
  O  O29  1  0.990  0.237  0.000  1.0
  O  O30  1  0.980  0.249  0.519  1.0
  O  O31  1  0.966  0.766  0.055  1.0
  O  O32  1  0.035  0.752  0.478  1.0
  O  O33  1  0.504  0.250  0.964  1.0
  O  O34  1  0.528  0.255  0.516  1.0
  O  O35  1  0.526  0.748  0.047  1.0
  O  O36  1  0.476  0.743  0.442  1.0
[/CIF]
.