The material structure described by Ca6Si3O13 crystallizes in the triclinic P-1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(13), one O(2), one O(4), one O(6), and two equivalent O(5) atoms. In the second Ca site, Ca(2) is bonded to one O(12), one O(6), one O(8), one O(9), and two equivalent O(7) atoms to form distorted CaO6 octahedra that share  a cornercorner with one Ca(3)O6 octahedra, corners with two equivalent Ca(5)O6 octahedra, corners with four equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Ca(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-78°. In the third Ca site, Ca(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form distorted CaO6 octahedra that share  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(5)O6 octahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Ca(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-21°. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(11), one O(3), one O(4), one O(6), one O(7), one O(8), and one O(9) atom. In the fifth Ca site, Ca(5) is bonded to one O(1), one O(11), one O(12), one O(13), one O(4), and one O(8) atom to form distorted CaO6 octahedra that share  a cornercorner with one Ca(3)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 21-78°. In the sixth Ca site, Ca(6) is bonded in a 8-coordinate geometry to one O(1), one O(11), one O(12), one O(13), one O(3), one O(6), one O(8), and one O(9) atom. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(2), and one O(4) atom to form SiO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  an edgeedge with one Ca(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-67°. In the second Si site, Si(2) is bonded to one O(10), one O(13), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(5)O6 octahedra, corners with two equivalent Ca(3)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-68°. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(5)O6 octahedra and corners with four equivalent Ca(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-65°. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded to one Ca(3), one Ca(5), one Ca(6), and one Si(1) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(9)Ca3Si trigonal pyramid,  a cornercorner with one O(6)Ca4 trigonal pyramid, corners with two equivalent O(12)Ca3Si trigonal pyramids, corners with two equivalent O(13)Ca3Si trigonal pyramids, and  an edgeedge with one O(11)Ca3Si trigonal pyramid. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Ca(3), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ca(3), one Ca(4), one Ca(6), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(3), one Ca(4), one Ca(5), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(3), two equivalent Ca(1), and one Si(2) atom. In the sixth O site, O(6) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Ca(6) atom to form a mixture of edge and corner-sharing OCa4 trigonal pyramids. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(4), two equivalent Ca(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), one Ca(5), and one Ca(6) atom. In the ninth O site, O(9) is bonded to one Ca(2), one Ca(4), one Ca(6), and one Si(3) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(1)Ca3Si trigonal pyramid,  a cornercorner with one O(12)Ca3Si trigonal pyramid,  a cornercorner with one O(13)Ca3Si trigonal pyramid, corners with three equivalent O(11)Ca3Si trigonal pyramids, corners with three equivalent O(6)Ca4 trigonal pyramids, and  an edgeedge with one O(12)Ca3Si trigonal pyramid. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the eleventh O site, O(11) is bonded to one Ca(4), one Ca(5), one Ca(6), and one Si(3) atom to form distorted OCa3Si trigonal pyramids that share corners with two equivalent O(13)Ca3Si trigonal pyramids, corners with three equivalent O(12)Ca3Si trigonal pyramids, corners with three equivalent O(9)Ca3Si trigonal pyramids,  an edgeedge with one O(1)Ca3Si trigonal pyramid, and  an edgeedge with one O(6)Ca4 trigonal pyramid. In the twelfth O site, O(12) is bonded to one Ca(2), one Ca(5), one Ca(6), and one Si(3) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(9)Ca3Si trigonal pyramid, corners with two equivalent O(1)Ca3Si trigonal pyramids, corners with three equivalent O(11)Ca3Si trigonal pyramids,  an edgeedge with one O(13)Ca3Si trigonal pyramid,  an edgeedge with one O(9)Ca3Si trigonal pyramid, and  an edgeedge with one O(6)Ca4 trigonal pyramid. In the thirteenth O site, O(13) is bonded to one Ca(1), one Ca(5), one Ca(6), and one Si(2) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(9)Ca3Si trigonal pyramid, corners with two equivalent O(1)Ca3Si trigonal pyramids, corners with two equivalent O(11)Ca3Si trigonal pyramids,  an edgeedge with one O(12)Ca3Si trigonal pyramid, and  an edgeedge with one O(6)Ca4 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca6Si3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.879
_cell_length_b   7.044
_cell_length_c   12.950
_cell_angle_alpha   91.002
_cell_angle_beta   98.091
_cell_angle_gamma   98.019
_symmetry_Int_Tables_number   1
_cell_volume   614.693
_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  0.911  0.815  0.890  1.0
  Ca  Ca1  1  0.089  0.185  0.110  1.0
  Ca  Ca2  1  0.814  0.804  0.512  1.0
  Ca  Ca3  1  0.186  0.196  0.488  1.0
  Ca  Ca4  1  0.686  0.807  0.124  1.0
  Ca  Ca5  1  0.314  0.193  0.876  1.0
  Ca  Ca6  1  0.449  0.965  0.680  1.0
  Ca  Ca7  1  0.551  0.035  0.320  1.0
  Ca  Ca8  1  0.107  0.531  0.710  1.0
  Ca  Ca9  1  0.893  0.469  0.290  1.0
  Ca  Ca10  1  0.408  0.532  0.295  1.0
  Ca  Ca11  1  0.592  0.468  0.705  1.0
  Si  Si12  1  0.386  0.714  0.902  1.0
  Si  Si13  1  0.614  0.286  0.098  1.0
  Si  Si14  1  0.189  0.713  0.114  1.0
  Si  Si15  1  0.811  0.287  0.886  1.0
  Si  Si16  1  0.287  0.698  0.491  1.0
  Si  Si17  1  0.713  0.302  0.509  1.0
  O  O18  1  0.387  0.514  0.835  1.0
  O  O19  1  0.613  0.486  0.165  1.0
  O  O20  1  0.608  0.816  0.947  1.0
  O  O21  1  0.392  0.184  0.053  1.0
  O  O22  1  0.384  0.815  0.194  1.0
  O  O23  1  0.616  0.185  0.806  1.0
  O  O24  1  0.251  0.847  0.823  1.0
  O  O25  1  0.749  0.153  0.177  1.0
  O  O26  1  0.012  0.847  0.087  1.0
  O  O27  1  0.988  0.153  0.913  1.0
  O  O28  1  0.753  0.825  0.697  1.0
  O  O29  1  0.247  0.175  0.303  1.0
  O  O30  1  0.155  0.867  0.513  1.0
  O  O31  1  0.845  0.133  0.487  1.0
  O  O32  1  0.789  0.780  0.317  1.0
  O  O33  1  0.211  0.220  0.683  1.0
  O  O34  1  0.478  0.784  0.434  1.0
  O  O35  1  0.522  0.216  0.566  1.0
  O  O36  1  0.258  0.662  0.000  1.0
  O  O37  1  0.742  0.338  1.000  1.0
  O  O38  1  0.364  0.631  0.610  1.0
  O  O39  1  0.636  0.369  0.390  1.0
  O  O40  1  0.168  0.512  0.418  1.0
  O  O41  1  0.832  0.488  0.582  1.0
  O  O42  1  0.885  0.489  0.832  1.0
  O  O43  1  0.115  0.511  0.168  1.0
[/CIF]
.
The material structure described by Ca6Si3O13 crystallizes in the triclinic P-1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(13), one O(2), one O(4), one O(6), and two equivalent O(5) atoms. In the second Ca site, Ca(2) is bonded to one O(12), one O(6), one O(8), one O(9), and two equivalent O(7) atoms to form distorted CaO6 octahedra that share  a cornercorner with one Ca(3)O6 octahedra, corners with two equivalent Ca(5)O6 octahedra, corners with four equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Ca(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-78°. In the third Ca site, Ca(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form distorted CaO6 octahedra that share  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(5)O6 octahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Ca(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-21°. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(11), one O(3), one O(4), one O(6), one O(7), one O(8), and one O(9) atom. In the fifth Ca site, Ca(5) is bonded to one O(1), one O(11), one O(12), one O(13), one O(4), and one O(8) atom to form distorted CaO6 octahedra that share  a cornercorner with one Ca(3)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 21-78°. In the sixth Ca site, Ca(6) is bonded in a 8-coordinate geometry to one O(1), one O(11), one O(12), one O(13), one O(3), one O(6), one O(8), and one O(9) atom. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(2), and one O(4) atom to form SiO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  an edgeedge with one Ca(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-67°. In the second Si site, Si(2) is bonded to one O(10), one O(13), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(5)O6 octahedra, corners with two equivalent Ca(3)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-68°. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(5)O6 octahedra and corners with four equivalent Ca(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-65°. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded to one Ca(3), one Ca(5), one Ca(6), and one Si(1) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(9)Ca3Si trigonal pyramid,  a cornercorner with one O(6)Ca4 trigonal pyramid, corners with two equivalent O(12)Ca3Si trigonal pyramids, corners with two equivalent O(13)Ca3Si trigonal pyramids, and  an edgeedge with one O(11)Ca3Si trigonal pyramid. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Ca(3), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ca(3), one Ca(4), one Ca(6), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(3), one Ca(4), one Ca(5), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(3), two equivalent Ca(1), and one Si(2) atom. In the sixth O site, O(6) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Ca(6) atom to form a mixture of edge and corner-sharing OCa4 trigonal pyramids. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(4), two equivalent Ca(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), one Ca(5), and one Ca(6) atom. In the ninth O site, O(9) is bonded to one Ca(2), one Ca(4), one Ca(6), and one Si(3) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(1)Ca3Si trigonal pyramid,  a cornercorner with one O(12)Ca3Si trigonal pyramid,  a cornercorner with one O(13)Ca3Si trigonal pyramid, corners with three equivalent O(11)Ca3Si trigonal pyramids, corners with three equivalent O(6)Ca4 trigonal pyramids, and  an edgeedge with one O(12)Ca3Si trigonal pyramid. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the eleventh O site, O(11) is bonded to one Ca(4), one Ca(5), one Ca(6), and one Si(3) atom to form distorted OCa3Si trigonal pyramids that share corners with two equivalent O(13)Ca3Si trigonal pyramids, corners with three equivalent O(12)Ca3Si trigonal pyramids, corners with three equivalent O(9)Ca3Si trigonal pyramids,  an edgeedge with one O(1)Ca3Si trigonal pyramid, and  an edgeedge with one O(6)Ca4 trigonal pyramid. In the twelfth O site, O(12) is bonded to one Ca(2), one Ca(5), one Ca(6), and one Si(3) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(9)Ca3Si trigonal pyramid, corners with two equivalent O(1)Ca3Si trigonal pyramids, corners with three equivalent O(11)Ca3Si trigonal pyramids,  an edgeedge with one O(13)Ca3Si trigonal pyramid,  an edgeedge with one O(9)Ca3Si trigonal pyramid, and  an edgeedge with one O(6)Ca4 trigonal pyramid. In the thirteenth O site, O(13) is bonded to one Ca(1), one Ca(5), one Ca(6), and one Si(2) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(9)Ca3Si trigonal pyramid, corners with two equivalent O(1)Ca3Si trigonal pyramids, corners with two equivalent O(11)Ca3Si trigonal pyramids,  an edgeedge with one O(12)Ca3Si trigonal pyramid, and  an edgeedge with one O(6)Ca4 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca6Si3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.879
_cell_length_b   7.044
_cell_length_c   12.950
_cell_angle_alpha   91.002
_cell_angle_beta   98.091
_cell_angle_gamma   98.019
_symmetry_Int_Tables_number   1
_cell_volume   614.693
_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  0.911  0.815  0.890  1.0
  Ca  Ca1  1  0.089  0.185  0.110  1.0
  Ca  Ca2  1  0.814  0.804  0.512  1.0
  Ca  Ca3  1  0.186  0.196  0.488  1.0
  Ca  Ca4  1  0.686  0.807  0.124  1.0
  Ca  Ca5  1  0.314  0.193  0.876  1.0
  Ca  Ca6  1  0.449  0.965  0.680  1.0
  Ca  Ca7  1  0.551  0.035  0.320  1.0
  Ca  Ca8  1  0.107  0.531  0.710  1.0
  Ca  Ca9  1  0.893  0.469  0.290  1.0
  Ca  Ca10  1  0.408  0.532  0.295  1.0
  Ca  Ca11  1  0.592  0.468  0.705  1.0
  Si  Si12  1  0.386  0.714  0.902  1.0
  Si  Si13  1  0.614  0.286  0.098  1.0
  Si  Si14  1  0.189  0.713  0.114  1.0
  Si  Si15  1  0.811  0.287  0.886  1.0
  Si  Si16  1  0.287  0.698  0.491  1.0
  Si  Si17  1  0.713  0.302  0.509  1.0
  O  O18  1  0.387  0.514  0.835  1.0
  O  O19  1  0.613  0.486  0.165  1.0
  O  O20  1  0.608  0.816  0.947  1.0
  O  O21  1  0.392  0.184  0.053  1.0
  O  O22  1  0.384  0.815  0.194  1.0
  O  O23  1  0.616  0.185  0.806  1.0
  O  O24  1  0.251  0.847  0.823  1.0
  O  O25  1  0.749  0.153  0.177  1.0
  O  O26  1  0.012  0.847  0.087  1.0
  O  O27  1  0.988  0.153  0.913  1.0
  O  O28  1  0.753  0.825  0.697  1.0
  O  O29  1  0.247  0.175  0.303  1.0
  O  O30  1  0.155  0.867  0.513  1.0
  O  O31  1  0.845  0.133  0.487  1.0
  O  O32  1  0.789  0.780  0.317  1.0
  O  O33  1  0.211  0.220  0.683  1.0
  O  O34  1  0.478  0.784  0.434  1.0
  O  O35  1  0.522  0.216  0.566  1.0
  O  O36  1  0.258  0.662  0.000  1.0
  O  O37  1  0.742  0.338  1.000  1.0
  O  O38  1  0.364  0.631  0.610  1.0
  O  O39  1  0.636  0.369  0.390  1.0
  O  O40  1  0.168  0.512  0.418  1.0
  O  O41  1  0.832  0.488  0.582  1.0
  O  O42  1  0.885  0.489  0.832  1.0
  O  O43  1  0.115  0.511  0.168  1.0
[/CIF]
.