The material structure described by Ca5(SiO3)6 crystallizes in the triclinic P1 space group. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(10), one O(18), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted CaO7 pentagonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, corners with two equivalent Si(6)O4 tetrahedra, edges with two equivalent Ca(2)O7 pentagonal bipyramids, and  an edgeedge with one Si(5)O4 tetrahedra. In the second Ca site, Ca(2) is bonded to one O(17), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom to form distorted CaO7 pentagonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(5)O4 tetrahedra, edges with two equivalent Ca(1)O7 pentagonal bipyramids, and  an edgeedge with one Si(6)O4 tetrahedra. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(14), one O(15), one O(16), and one O(2) atom. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(17), one O(18), one O(2), one O(4), one O(6), one O(7), and one O(8) atom. In the fifth Ca site, Ca(5) is bonded in a 7-coordinate geometry to one O(1), one O(17), one O(18), one O(3), one O(5), one O(7), and one O(8) atom. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(11), and one O(13) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O7 pentagonal bipyramid,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(12), one O(14), one O(2), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O7 pentagonal bipyramid,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(13), one O(15), one O(17), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(2)O7 pentagonal bipyramids,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(14), one O(16), one O(18), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(11), one O(15), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(2)O7 pentagonal bipyramids,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  an edgeedge with one Ca(1)O7 pentagonal bipyramid. In the sixth Si site, Si(6) is bonded to one O(12), one O(16), one O(4), and one O(6) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Ca(2)O7 pentagonal bipyramid. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(3), one Ca(5), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(3), one Ca(4), and one Si(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(5), and one Si(5) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(4), and one Si(6) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(5), and one Si(5) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(4), and one Si(6) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(4), one Ca(5), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(4), one Ca(5), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted linear geometry to one Ca(2) and one Si(2) atom. In the tenth O site, O(10) is bonded in a distorted linear geometry to one Ca(1) and one Si(1) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(3), one Si(1), and one Si(5) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Si(2) and one Si(6) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ca(3), one Si(2), and one Si(4) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Ca(3), one Si(3), and one Si(5) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Ca(3), one Si(4), and one Si(6) atom. In the seventeenth O site, O(17) is bonded to one Ca(2), one Ca(4), one Ca(5), and one Si(3) atom to form distorted edge-sharing OCa3Si tetrahedra. In the eighteenth O site, O(18) is bonded to one Ca(1), one Ca(4), one Ca(5), and one Si(4) atom to form distorted edge-sharing OCa3Si tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca5(SiO3)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.720
_cell_length_b   6.722
_cell_length_c   9.619
_cell_angle_alpha   92.975
_cell_angle_beta   98.503
_cell_angle_gamma   113.300
_symmetry_Int_Tables_number   1
_cell_volume   391.752
_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
  Ca  Ca0  1  0.531  0.275  0.110  1.0
  Ca  Ca1  1  0.469  0.725  0.891  1.0
  Ca  Ca2  1  0.045  0.044  0.499  1.0
  Ca  Ca3  1  0.037  0.766  0.115  1.0
  Ca  Ca4  1  0.963  0.234  0.884  1.0
  Si  Si5  1  0.700  0.341  0.565  1.0
  Si  Si6  1  0.300  0.659  0.435  1.0
  Si  Si7  1  0.968  0.745  0.783  1.0
  Si  Si8  1  0.030  0.255  0.215  1.0
  Si  Si9  1  0.398  0.171  0.779  1.0
  Si  Si10  1  0.604  0.828  0.223  1.0
  O  O11  1  0.854  0.213  0.610  1.0
  O  O12  1  0.147  0.788  0.389  1.0
  O  O13  1  0.575  0.105  0.873  1.0
  O  O14  1  0.429  0.897  0.128  1.0
  O  O15  1  0.348  0.349  0.869  1.0
  O  O16  1  0.653  0.650  0.131  1.0
  O  O17  1  0.840  0.844  0.877  1.0
  O  O18  1  0.161  0.158  0.123  1.0
  O  O19  1  0.353  0.674  0.609  1.0
  O  O20  1  0.646  0.324  0.391  1.0
  O  O21  1  0.458  0.238  0.621  1.0
  O  O22  1  0.536  0.757  0.377  1.0
  O  O23  1  0.815  0.599  0.633  1.0
  O  O24  1  0.180  0.395  0.369  1.0
  O  O25  1  0.153  0.959  0.723  1.0
  O  O26  1  0.848  0.042  0.277  1.0
  O  O27  1  0.086  0.619  0.880  1.0
  O  O28  1  0.915  0.383  0.119  1.0
[/CIF]
.
The material structure described by Ca5(SiO3)6 crystallizes in the triclinic P1 space group. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(10), one O(18), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted CaO7 pentagonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, corners with two equivalent Si(6)O4 tetrahedra, edges with two equivalent Ca(2)O7 pentagonal bipyramids, and  an edgeedge with one Si(5)O4 tetrahedra. In the second Ca site, Ca(2) is bonded to one O(17), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom to form distorted CaO7 pentagonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(5)O4 tetrahedra, edges with two equivalent Ca(1)O7 pentagonal bipyramids, and  an edgeedge with one Si(6)O4 tetrahedra. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(14), one O(15), one O(16), and one O(2) atom. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(17), one O(18), one O(2), one O(4), one O(6), one O(7), and one O(8) atom. In the fifth Ca site, Ca(5) is bonded in a 7-coordinate geometry to one O(1), one O(17), one O(18), one O(3), one O(5), one O(7), and one O(8) atom. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(11), and one O(13) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O7 pentagonal bipyramid,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(12), one O(14), one O(2), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O7 pentagonal bipyramid,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(13), one O(15), one O(17), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(2)O7 pentagonal bipyramids,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(14), one O(16), one O(18), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(11), one O(15), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(2)O7 pentagonal bipyramids,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  an edgeedge with one Ca(1)O7 pentagonal bipyramid. In the sixth Si site, Si(6) is bonded to one O(12), one O(16), one O(4), and one O(6) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one Ca(2)O7 pentagonal bipyramid. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(3), one Ca(5), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(3), one Ca(4), and one Si(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(5), and one Si(5) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(4), and one Si(6) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(5), and one Si(5) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(4), and one Si(6) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(4), one Ca(5), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(4), one Ca(5), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted linear geometry to one Ca(2) and one Si(2) atom. In the tenth O site, O(10) is bonded in a distorted linear geometry to one Ca(1) and one Si(1) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(3), one Si(1), and one Si(5) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Si(2) and one Si(6) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ca(3), one Si(2), and one Si(4) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Ca(3), one Si(3), and one Si(5) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Ca(3), one Si(4), and one Si(6) atom. In the seventeenth O site, O(17) is bonded to one Ca(2), one Ca(4), one Ca(5), and one Si(3) atom to form distorted edge-sharing OCa3Si tetrahedra. In the eighteenth O site, O(18) is bonded to one Ca(1), one Ca(4), one Ca(5), and one Si(4) atom to form distorted edge-sharing OCa3Si tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca5(SiO3)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.720
_cell_length_b   6.722
_cell_length_c   9.619
_cell_angle_alpha   92.975
_cell_angle_beta   98.503
_cell_angle_gamma   113.300
_symmetry_Int_Tables_number   1
_cell_volume   391.752
_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
  Ca  Ca0  1  0.531  0.275  0.110  1.0
  Ca  Ca1  1  0.469  0.725  0.891  1.0
  Ca  Ca2  1  0.045  0.044  0.499  1.0
  Ca  Ca3  1  0.037  0.766  0.115  1.0
  Ca  Ca4  1  0.963  0.234  0.884  1.0
  Si  Si5  1  0.700  0.341  0.565  1.0
  Si  Si6  1  0.300  0.659  0.435  1.0
  Si  Si7  1  0.968  0.745  0.783  1.0
  Si  Si8  1  0.030  0.255  0.215  1.0
  Si  Si9  1  0.398  0.171  0.779  1.0
  Si  Si10  1  0.604  0.828  0.223  1.0
  O  O11  1  0.854  0.213  0.610  1.0
  O  O12  1  0.147  0.788  0.389  1.0
  O  O13  1  0.575  0.105  0.873  1.0
  O  O14  1  0.429  0.897  0.128  1.0
  O  O15  1  0.348  0.349  0.869  1.0
  O  O16  1  0.653  0.650  0.131  1.0
  O  O17  1  0.840  0.844  0.877  1.0
  O  O18  1  0.161  0.158  0.123  1.0
  O  O19  1  0.353  0.674  0.609  1.0
  O  O20  1  0.646  0.324  0.391  1.0
  O  O21  1  0.458  0.238  0.621  1.0
  O  O22  1  0.536  0.757  0.377  1.0
  O  O23  1  0.815  0.599  0.633  1.0
  O  O24  1  0.180  0.395  0.369  1.0
  O  O25  1  0.153  0.959  0.723  1.0
  O  O26  1  0.848  0.042  0.277  1.0
  O  O27  1  0.086  0.619  0.880  1.0
  O  O28  1  0.915  0.383  0.119  1.0
[/CIF]
.