The crystal structure described by Ca7Si6CO23 crystallizes in the monoclinic Cm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(13), one O(6), one O(7), 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(12), one O(14), one O(4), one O(5), 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(13), one O(2), two equivalent O(14), two equivalent O(7), and two equivalent O(8) atoms. In the fourth Ca site, Ca(4) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form distorted CaO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(4)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 50-58°. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-58°. In the third Si site, Si(3) is bonded to one O(10), one O(3), one O(4), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(4)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-62°. C(1) is bonded in a trigonal planar geometry to one O(13) and two equivalent O(14) atoms. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(3) and two equivalent Si(2) atoms. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ca(3) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(2), one Si(2), and one Si(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(4), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ca(4), and one Si(1) atom. In the seventh O site, O(7) is bonded to one Ca(1), one Ca(3), one Ca(4), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OCa3Si tetrahedra. In the eighth O site, O(8) is bonded to one Ca(2), one Ca(3), one Ca(4), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCa3Si tetrahedra. In the ninth O site, O(9) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the tenth O site, O(10) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCa3Si tetrahedra. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to two equivalent Ca(1) atoms. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to two equivalent Ca(2) atoms. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Ca(3), two equivalent Ca(1), and one C(1) atom. In the fourteenth O site, O(14) is bonded in a 1-coordinate geometry to one Ca(2), one Ca(3), and one C(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca7Si6CO23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.481
_cell_length_b   9.481
_cell_length_c   6.692
_cell_angle_alpha   75.333
_cell_angle_beta   75.333
_cell_angle_gamma   107.932
_symmetry_Int_Tables_number   1
_cell_volume   516.638
_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  0.652  0.931  0.015  1.0
  Ca  Ca1  1  0.081  0.364  0.982  1.0
  Ca  Ca2  1  0.364  0.081  0.982  1.0
  Ca  Ca3  1  0.931  0.652  0.015  1.0
  Ca  Ca4  1  0.995  0.995  0.478  1.0
  Ca  Ca5  1  0.253  0.751  0.497  1.0
  Ca  Ca6  1  0.751  0.253  0.497  1.0
  Si  Si7  1  0.832  0.625  0.568  1.0
  Si  Si8  1  0.376  0.169  0.433  1.0
  Si  Si9  1  0.169  0.376  0.433  1.0
  Si  Si10  1  0.625  0.832  0.568  1.0
  Si  Si11  1  0.679  0.328  0.999  1.0
  Si  Si12  1  0.328  0.679  0.999  1.0
  C  C13  1  0.984  0.984  0.020  1.0
  O  O14  1  0.254  0.254  0.520  1.0
  O  O15  1  0.754  0.754  0.482  1.0
  O  O16  1  0.705  0.493  0.811  1.0
  O  O17  1  0.507  0.289  0.186  1.0
  O  O18  1  0.289  0.507  0.186  1.0
  O  O19  1  0.493  0.705  0.811  1.0
  O  O20  1  0.137  0.464  0.606  1.0
  O  O21  1  0.538  0.863  0.393  1.0
  O  O22  1  0.863  0.538  0.393  1.0
  O  O23  1  0.464  0.137  0.606  1.0
  O  O24  1  0.985  0.729  0.613  1.0
  O  O25  1  0.266  0.017  0.391  1.0
  O  O26  1  0.017  0.266  0.391  1.0
  O  O27  1  0.729  0.985  0.613  1.0
  O  O28  1  0.653  0.185  0.900  1.0
  O  O29  1  0.822  0.364  0.097  1.0
  O  O30  1  0.364  0.822  0.097  1.0
  O  O31  1  0.185  0.653  0.900  1.0
  O  O32  1  0.669  0.669  0.124  1.0
  O  O33  1  0.310  0.310  0.898  1.0
  O  O34  1  0.918  0.918  0.896  1.0
  O  O35  1  0.939  0.085  0.083  1.0
  O  O36  1  0.085  0.939  0.083  1.0
[/CIF]
.
The crystal structure described by Ca7Si6CO23 crystallizes in the monoclinic Cm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(13), one O(6), one O(7), 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(12), one O(14), one O(4), one O(5), 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(13), one O(2), two equivalent O(14), two equivalent O(7), and two equivalent O(8) atoms. In the fourth Ca site, Ca(4) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form distorted CaO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(4)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 50-58°. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(4)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-58°. In the third Si site, Si(3) is bonded to one O(10), one O(3), one O(4), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(4)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-62°. C(1) is bonded in a trigonal planar geometry to one O(13) and two equivalent O(14) atoms. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(3) and two equivalent Si(2) atoms. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ca(3) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(2), one Si(2), and one Si(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(4), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ca(4), and one Si(1) atom. In the seventh O site, O(7) is bonded to one Ca(1), one Ca(3), one Ca(4), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OCa3Si tetrahedra. In the eighth O site, O(8) is bonded to one Ca(2), one Ca(3), one Ca(4), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCa3Si tetrahedra. In the ninth O site, O(9) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the tenth O site, O(10) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCa3Si tetrahedra. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to two equivalent Ca(1) atoms. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to two equivalent Ca(2) atoms. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Ca(3), two equivalent Ca(1), and one C(1) atom. In the fourteenth O site, O(14) is bonded in a 1-coordinate geometry to one Ca(2), one Ca(3), and one C(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca7Si6CO23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.481
_cell_length_b   9.481
_cell_length_c   6.692
_cell_angle_alpha   75.333
_cell_angle_beta   75.333
_cell_angle_gamma   107.932
_symmetry_Int_Tables_number   1
_cell_volume   516.638
_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  0.652  0.931  0.015  1.0
  Ca  Ca1  1  0.081  0.364  0.982  1.0
  Ca  Ca2  1  0.364  0.081  0.982  1.0
  Ca  Ca3  1  0.931  0.652  0.015  1.0
  Ca  Ca4  1  0.995  0.995  0.478  1.0
  Ca  Ca5  1  0.253  0.751  0.497  1.0
  Ca  Ca6  1  0.751  0.253  0.497  1.0
  Si  Si7  1  0.832  0.625  0.568  1.0
  Si  Si8  1  0.376  0.169  0.433  1.0
  Si  Si9  1  0.169  0.376  0.433  1.0
  Si  Si10  1  0.625  0.832  0.568  1.0
  Si  Si11  1  0.679  0.328  0.999  1.0
  Si  Si12  1  0.328  0.679  0.999  1.0
  C  C13  1  0.984  0.984  0.020  1.0
  O  O14  1  0.254  0.254  0.520  1.0
  O  O15  1  0.754  0.754  0.482  1.0
  O  O16  1  0.705  0.493  0.811  1.0
  O  O17  1  0.507  0.289  0.186  1.0
  O  O18  1  0.289  0.507  0.186  1.0
  O  O19  1  0.493  0.705  0.811  1.0
  O  O20  1  0.137  0.464  0.606  1.0
  O  O21  1  0.538  0.863  0.393  1.0
  O  O22  1  0.863  0.538  0.393  1.0
  O  O23  1  0.464  0.137  0.606  1.0
  O  O24  1  0.985  0.729  0.613  1.0
  O  O25  1  0.266  0.017  0.391  1.0
  O  O26  1  0.017  0.266  0.391  1.0
  O  O27  1  0.729  0.985  0.613  1.0
  O  O28  1  0.653  0.185  0.900  1.0
  O  O29  1  0.822  0.364  0.097  1.0
  O  O30  1  0.364  0.822  0.097  1.0
  O  O31  1  0.185  0.653  0.900  1.0
  O  O32  1  0.669  0.669  0.124  1.0
  O  O33  1  0.310  0.310  0.898  1.0
  O  O34  1  0.918  0.918  0.896  1.0
  O  O35  1  0.939  0.085  0.083  1.0
  O  O36  1  0.085  0.939  0.083  1.0
[/CIF]
.