The material structure described by Ca2Fe2Si5HO15 is Esseneite-derived structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(13), one O(14), and two equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(12), one O(4), one O(5), one O(6), one O(7), one O(8), and two equivalent O(9) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(13), one O(4), one O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(14), one O(2), one O(4), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(15), one O(2), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-62°. In the third Si site, Si(3) is bonded to one O(6), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-64°. In the fourth Si site, Si(4) is bonded to one O(10), one O(11), one O(12), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-66°. In the fifth Si site, Si(5) is bonded to one O(12), one O(13), one O(14), and one O(15) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-51°. H(1) is bonded in a linear geometry to one O(1) and one O(11) atom. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Si(1), and one H(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Fe(2), and one Si(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(4) is bonded to one Ca(2), one Fe(1), one Fe(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCaFe2Si tetrahedra. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Ca(2), one Fe(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(2), one Si(2), and one Si(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(2), one Fe(2), and one Si(3) atom. In the eighth O site, O(8) is bonded to one Ca(2), two equivalent Fe(1), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCaFe2Si tetrahedra. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Ca(2), one Si(3), and one Si(4) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Ca(1), one Fe(1), one Fe(2), and one Si(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Fe(2), one Si(4), and one H(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Ca(2), one Si(4), and one Si(5) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Ca(1), one Fe(1), and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Fe(2), and one Si(5) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Si(1) and one Si(5) atom. is represented by the CIF file [CIF]
data_Ca2Fe2Si5HO15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.790
_cell_length_b   7.589
_cell_length_c   11.768
_cell_angle_alpha   104.408
_cell_angle_beta   91.819
_cell_angle_gamma   94.022
_symmetry_Int_Tables_number   1
_cell_volume   585.132
_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  0.860  0.219  0.058  1.0
  Ca  Ca1  1  0.140  0.781  0.942  1.0
  Ca  Ca2  1  0.701  0.762  0.478  1.0
  Ca  Ca3  1  0.299  0.238  0.522  1.0
  Fe  Fe4  1  0.940  0.406  0.355  1.0
  Fe  Fe5  1  0.060  0.594  0.645  1.0
  Fe  Fe6  1  0.814  0.954  0.765  1.0
  Fe  Fe7  1  0.186  0.046  0.235  1.0
  Si  Si8  1  0.659  0.714  0.946  1.0
  Si  Si9  1  0.341  0.286  0.054  1.0
  Si  Si10  1  0.575  0.540  0.686  1.0
  Si  Si11  1  0.425  0.460  0.314  1.0
  Si  Si12  1  0.789  0.194  0.554  1.0
  Si  Si13  1  0.211  0.806  0.446  1.0
  Si  Si14  1  0.691  0.012  0.285  1.0
  Si  Si15  1  0.309  0.988  0.715  1.0
  Si  Si16  1  0.893  0.674  0.164  1.0
  Si  Si17  1  0.107  0.326  0.836  1.0
  H  H18  1  0.522  0.114  0.905  1.0
  H  H19  1  0.478  0.886  0.095  1.0
  O  O20  1  0.465  0.803  0.011  1.0
  O  O21  1  0.535  0.197  0.989  1.0
  O  O22  1  0.817  0.871  0.919  1.0
  O  O23  1  0.183  0.129  0.081  1.0
  O  O24  1  0.567  0.567  0.828  1.0
  O  O25  1  0.433  0.433  0.172  1.0
  O  O26  1  0.752  0.684  0.660  1.0
  O  O27  1  0.248  0.316  0.340  1.0
  O  O28  1  0.637  0.454  0.379  1.0
  O  O29  1  0.363  0.546  0.621  1.0
  O  O30  1  0.627  0.324  0.627  1.0
  O  O31  1  0.373  0.676  0.373  1.0
  O  O32  1  0.838  0.032  0.615  1.0
  O  O33  1  0.162  0.968  0.385  1.0
  O  O34  1  0.973  0.321  0.524  1.0
  O  O35  1  0.027  0.679  0.476  1.0
  O  O36  1  0.662  0.074  0.430  1.0
  O  O37  1  0.338  0.926  0.570  1.0
  O  O38  1  0.876  0.128  0.244  1.0
  O  O39  1  0.124  0.872  0.756  1.0
  O  O40  1  0.520  0.983  0.781  1.0
  O  O41  1  0.480  0.017  0.219  1.0
  O  O42  1  0.751  0.797  0.264  1.0
  O  O43  1  0.249  0.203  0.736  1.0
  O  O44  1  0.939  0.490  0.200  1.0
  O  O45  1  0.061  0.510  0.800  1.0
  O  O46  1  0.919  0.195  0.858  1.0
  O  O47  1  0.081  0.805  0.142  1.0
  O  O48  1  0.772  0.609  0.033  1.0
  O  O49  1  0.228  0.391  0.967  1.0
[/CIF]
.
The material structure described by Ca2Fe2Si5HO15 is Esseneite-derived structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(13), one O(14), and two equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(12), one O(4), one O(5), one O(6), one O(7), one O(8), and two equivalent O(9) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(13), one O(4), one O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(14), one O(2), one O(4), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(15), one O(2), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-62°. In the third Si site, Si(3) is bonded to one O(6), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-64°. In the fourth Si site, Si(4) is bonded to one O(10), one O(11), one O(12), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-66°. In the fifth Si site, Si(5) is bonded to one O(12), one O(13), one O(14), and one O(15) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-51°. H(1) is bonded in a linear geometry to one O(1) and one O(11) atom. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Si(1), and one H(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Fe(2), and one Si(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(4) is bonded to one Ca(2), one Fe(1), one Fe(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCaFe2Si tetrahedra. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Ca(2), one Fe(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(2), one Si(2), and one Si(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(2), one Fe(2), and one Si(3) atom. In the eighth O site, O(8) is bonded to one Ca(2), two equivalent Fe(1), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCaFe2Si tetrahedra. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Ca(2), one Si(3), and one Si(4) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Ca(1), one Fe(1), one Fe(2), and one Si(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Fe(2), one Si(4), and one H(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Ca(2), one Si(4), and one Si(5) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Ca(1), one Fe(1), and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Fe(2), and one Si(5) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Si(1) and one Si(5) atom. is represented by the CIF file [CIF]
data_Ca2Fe2Si5HO15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.790
_cell_length_b   7.589
_cell_length_c   11.768
_cell_angle_alpha   104.408
_cell_angle_beta   91.819
_cell_angle_gamma   94.022
_symmetry_Int_Tables_number   1
_cell_volume   585.132
_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  0.860  0.219  0.058  1.0
  Ca  Ca1  1  0.140  0.781  0.942  1.0
  Ca  Ca2  1  0.701  0.762  0.478  1.0
  Ca  Ca3  1  0.299  0.238  0.522  1.0
  Fe  Fe4  1  0.940  0.406  0.355  1.0
  Fe  Fe5  1  0.060  0.594  0.645  1.0
  Fe  Fe6  1  0.814  0.954  0.765  1.0
  Fe  Fe7  1  0.186  0.046  0.235  1.0
  Si  Si8  1  0.659  0.714  0.946  1.0
  Si  Si9  1  0.341  0.286  0.054  1.0
  Si  Si10  1  0.575  0.540  0.686  1.0
  Si  Si11  1  0.425  0.460  0.314  1.0
  Si  Si12  1  0.789  0.194  0.554  1.0
  Si  Si13  1  0.211  0.806  0.446  1.0
  Si  Si14  1  0.691  0.012  0.285  1.0
  Si  Si15  1  0.309  0.988  0.715  1.0
  Si  Si16  1  0.893  0.674  0.164  1.0
  Si  Si17  1  0.107  0.326  0.836  1.0
  H  H18  1  0.522  0.114  0.905  1.0
  H  H19  1  0.478  0.886  0.095  1.0
  O  O20  1  0.465  0.803  0.011  1.0
  O  O21  1  0.535  0.197  0.989  1.0
  O  O22  1  0.817  0.871  0.919  1.0
  O  O23  1  0.183  0.129  0.081  1.0
  O  O24  1  0.567  0.567  0.828  1.0
  O  O25  1  0.433  0.433  0.172  1.0
  O  O26  1  0.752  0.684  0.660  1.0
  O  O27  1  0.248  0.316  0.340  1.0
  O  O28  1  0.637  0.454  0.379  1.0
  O  O29  1  0.363  0.546  0.621  1.0
  O  O30  1  0.627  0.324  0.627  1.0
  O  O31  1  0.373  0.676  0.373  1.0
  O  O32  1  0.838  0.032  0.615  1.0
  O  O33  1  0.162  0.968  0.385  1.0
  O  O34  1  0.973  0.321  0.524  1.0
  O  O35  1  0.027  0.679  0.476  1.0
  O  O36  1  0.662  0.074  0.430  1.0
  O  O37  1  0.338  0.926  0.570  1.0
  O  O38  1  0.876  0.128  0.244  1.0
  O  O39  1  0.124  0.872  0.756  1.0
  O  O40  1  0.520  0.983  0.781  1.0
  O  O41  1  0.480  0.017  0.219  1.0
  O  O42  1  0.751  0.797  0.264  1.0
  O  O43  1  0.249  0.203  0.736  1.0
  O  O44  1  0.939  0.490  0.200  1.0
  O  O45  1  0.061  0.510  0.800  1.0
  O  O46  1  0.919  0.195  0.858  1.0
  O  O47  1  0.081  0.805  0.142  1.0
  O  O48  1  0.772  0.609  0.033  1.0
  O  O49  1  0.228  0.391  0.967  1.0
[/CIF]
.