The compound described by Ca4Si3O11 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form distorted CaO6 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,  an edgeedge with one Ca(1)O6 octahedra, and edges with three equivalent Ca(2)O6 octahedra. In the second Ca site, Ca(2) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(1) atoms to form distorted CaO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra, and edges with three equivalent Ca(1)O6 octahedra. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(5), one O(8), one O(9), and two equivalent O(7) atoms. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(10), one O(3), one O(4), one O(6), one O(7), and two equivalent O(8) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(3), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with three equivalent Ca(2)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 27-66°. In the second Si site, Si(2) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)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 49-64°. In the third Si site, Si(3) is bonded to one O(10), one O(11), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)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 51-66°. There are eleven inequivalent O sites. In the first O site, O(10) is bonded in a 3-coordinate geometry to one Ca(4), one Si(1), and one Si(3) atom. In the second O site, O(11) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the third O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Ca(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a trigonal non-coplanar geometry to one Ca(2) and two equivalent Ca(1) atoms. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), and one Si(1) atom. In the sixth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Ca(1), one Ca(3), and one Ca(4) atom. In the seventh O site, O(5) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Si(2) atom to form distorted corner-sharing OCa3Si tetrahedra. In the eighth O site, O(6) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Si(3) atom to form distorted corner-sharing OCa3Si tetrahedra. In the ninth O site, O(7) is bonded in a 3-coordinate geometry to one Ca(4), two equivalent Ca(3), and one Si(2) atom. In the tenth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(3), two equivalent Ca(4), and one Si(3) atom. In the eleventh O site, O(9) is bonded in a 3-coordinate geometry to one Ca(3), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_Ca4Si3O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.962
_cell_length_b   7.489
_cell_length_c   10.582
_cell_angle_alpha   90.492
_cell_angle_beta   107.759
_cell_angle_gamma   90.135
_symmetry_Int_Tables_number   1
_cell_volume   525.380
_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  0.349  0.632  0.578  1.0
  Ca  Ca1  1  0.651  0.368  0.422  1.0
  Ca  Ca2  1  0.363  0.118  0.594  1.0
  Ca  Ca3  1  0.637  0.882  0.406  1.0
  Ca  Ca4  1  0.256  0.873  0.870  1.0
  Ca  Ca5  1  0.744  0.127  0.130  1.0
  Ca  Ca6  1  0.254  0.376  0.865  1.0
  Ca  Ca7  1  0.746  0.624  0.135  1.0
  Si  Si8  1  0.895  0.121  0.710  1.0
  Si  Si9  1  0.105  0.879  0.290  1.0
  Si  Si10  1  0.703  0.834  0.844  1.0
  Si  Si11  1  0.297  0.166  0.156  1.0
  Si  Si12  1  0.699  0.415  0.839  1.0
  Si  Si13  1  0.301  0.585  0.161  1.0
  O  O14  1  0.714  0.117  0.571  1.0
  O  O15  1  0.286  0.883  0.429  1.0
  O  O16  1  0.661  0.633  0.535  1.0
  O  O17  1  0.339  0.367  0.465  1.0
  O  O18  1  0.124  0.124  0.705  1.0
  O  O19  1  0.876  0.876  0.295  1.0
  O  O20  1  0.159  0.624  0.723  1.0
  O  O21  1  0.841  0.376  0.277  1.0
  O  O22  1  0.484  0.871  0.736  1.0
  O  O23  1  0.516  0.129  0.264  1.0
  O  O24  1  0.479  0.378  0.730  1.0
  O  O25  1  0.521  0.622  0.270  1.0
  O  O26  1  0.693  0.877  0.991  1.0
  O  O27  1  0.307  0.123  0.009  1.0
  O  O28  1  0.682  0.371  0.985  1.0
  O  O29  1  0.318  0.629  0.015  1.0
  O  O30  1  0.885  0.946  0.805  1.0
  O  O31  1  0.115  0.054  0.195  1.0
  O  O32  1  0.880  0.302  0.801  1.0
  O  O33  1  0.120  0.698  0.199  1.0
  O  O34  1  0.773  0.624  0.837  1.0
  O  O35  1  0.227  0.376  0.163  1.0
[/CIF]
.
The compound described by Ca4Si3O11 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form distorted CaO6 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,  an edgeedge with one Ca(1)O6 octahedra, and edges with three equivalent Ca(2)O6 octahedra. In the second Ca site, Ca(2) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(1) atoms to form distorted CaO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra, and edges with three equivalent Ca(1)O6 octahedra. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(5), one O(8), one O(9), and two equivalent O(7) atoms. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(10), one O(3), one O(4), one O(6), one O(7), and two equivalent O(8) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(3), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with three equivalent Ca(2)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 27-66°. In the second Si site, Si(2) is bonded to one O(11), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)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 49-64°. In the third Si site, Si(3) is bonded to one O(10), one O(11), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)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 51-66°. There are eleven inequivalent O sites. In the first O site, O(10) is bonded in a 3-coordinate geometry to one Ca(4), one Si(1), and one Si(3) atom. In the second O site, O(11) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the third O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Ca(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a trigonal non-coplanar geometry to one Ca(2) and two equivalent Ca(1) atoms. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), and one Si(1) atom. In the sixth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Ca(1), one Ca(3), and one Ca(4) atom. In the seventh O site, O(5) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Si(2) atom to form distorted corner-sharing OCa3Si tetrahedra. In the eighth O site, O(6) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Si(3) atom to form distorted corner-sharing OCa3Si tetrahedra. In the ninth O site, O(7) is bonded in a 3-coordinate geometry to one Ca(4), two equivalent Ca(3), and one Si(2) atom. In the tenth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(3), two equivalent Ca(4), and one Si(3) atom. In the eleventh O site, O(9) is bonded in a 3-coordinate geometry to one Ca(3), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_Ca4Si3O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.962
_cell_length_b   7.489
_cell_length_c   10.582
_cell_angle_alpha   90.492
_cell_angle_beta   107.759
_cell_angle_gamma   90.135
_symmetry_Int_Tables_number   1
_cell_volume   525.380
_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  0.349  0.632  0.578  1.0
  Ca  Ca1  1  0.651  0.368  0.422  1.0
  Ca  Ca2  1  0.363  0.118  0.594  1.0
  Ca  Ca3  1  0.637  0.882  0.406  1.0
  Ca  Ca4  1  0.256  0.873  0.870  1.0
  Ca  Ca5  1  0.744  0.127  0.130  1.0
  Ca  Ca6  1  0.254  0.376  0.865  1.0
  Ca  Ca7  1  0.746  0.624  0.135  1.0
  Si  Si8  1  0.895  0.121  0.710  1.0
  Si  Si9  1  0.105  0.879  0.290  1.0
  Si  Si10  1  0.703  0.834  0.844  1.0
  Si  Si11  1  0.297  0.166  0.156  1.0
  Si  Si12  1  0.699  0.415  0.839  1.0
  Si  Si13  1  0.301  0.585  0.161  1.0
  O  O14  1  0.714  0.117  0.571  1.0
  O  O15  1  0.286  0.883  0.429  1.0
  O  O16  1  0.661  0.633  0.535  1.0
  O  O17  1  0.339  0.367  0.465  1.0
  O  O18  1  0.124  0.124  0.705  1.0
  O  O19  1  0.876  0.876  0.295  1.0
  O  O20  1  0.159  0.624  0.723  1.0
  O  O21  1  0.841  0.376  0.277  1.0
  O  O22  1  0.484  0.871  0.736  1.0
  O  O23  1  0.516  0.129  0.264  1.0
  O  O24  1  0.479  0.378  0.730  1.0
  O  O25  1  0.521  0.622  0.270  1.0
  O  O26  1  0.693  0.877  0.991  1.0
  O  O27  1  0.307  0.123  0.009  1.0
  O  O28  1  0.682  0.371  0.985  1.0
  O  O29  1  0.318  0.629  0.015  1.0
  O  O30  1  0.885  0.946  0.805  1.0
  O  O31  1  0.115  0.054  0.195  1.0
  O  O32  1  0.880  0.302  0.801  1.0
  O  O33  1  0.120  0.698  0.199  1.0
  O  O34  1  0.773  0.624  0.837  1.0
  O  O35  1  0.227  0.376  0.163  1.0
[/CIF]
.