The material structure described by K2Ca3Si3O10 crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(2), one O(6), one O(8), one O(9), two equivalent O(4), and three equivalent O(1) atoms. In the second K site, K(2) is bonded to one O(1), one O(10), one O(5), one O(6), one O(7), one O(9), and two equivalent O(8) atoms to form distorted KO8 hexagonal bipyramids that share corners with two equivalent K(2)O8 hexagonal bipyramids,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, edges with two equivalent Ca(2)O6 octahedra,  an edgeedge with one Si(3)O4 tetrahedra, edges with two equivalent Si(2)O4 tetrahedra,  a faceface with one Ca(1)O6 octahedra, and  a faceface with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted CaO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra,  a faceface with one K(2)O8 hexagonal bipyramid, and  a faceface with one Ca(2)O6 octahedra. In the second Ca site, Ca(2) is bonded to one O(3), one O(5), one O(6), one O(9), and two equivalent O(10) atoms to form distorted CaO6 octahedra that share  a cornercorner with one K(2)O8 hexagonal bipyramid,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Si(3)O4 tetrahedra, edges with two equivalent K(2)O8 hexagonal bipyramids,  an edgeedge with one Ca(2)O6 octahedra, and  a faceface with one Ca(1)O6 octahedra. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), 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(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one K(2)O8 hexagonal bipyramid,  a cornercorner with one Ca(2)O6 octahedra, and corners with four equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-64°. In the second Si site, Si(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one K(2)O8 hexagonal bipyramid, corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent K(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 20-68°. In the third Si site, Si(3) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one K(2)O8 hexagonal bipyramid, and  a faceface with one K(2)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 50-65°. There are ten inequivalent O sites. In the first O site, O(9) is bonded in a 3-coordinate geometry to one K(1), one K(2), one Ca(2), one Ca(3), and one Si(3) atom. In the second O site, O(10) is bonded in a 4-coordinate geometry to one K(2), two equivalent Ca(2), and one Si(3) atom. In the third O site, O(1) is bonded in a 6-coordinate geometry to one K(2), three equivalent K(1), one Ca(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal pyramidal geometry to one K(1), one Ca(1), one Ca(3), and one Si(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), and one Si(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent K(1), one Ca(1), one Ca(3), and one Si(1) atom. In the seventh O site, O(5) is bonded in a 5-coordinate geometry to one K(2), one Ca(1), one Ca(2), one Ca(3), and one Si(2) atom. In the eighth O site, O(6) is bonded in a 1-coordinate geometry to one K(1), one K(2), one Ca(1), one Ca(2), one Ca(3), and one Si(2) atom. In the ninth O site, O(7) is bonded in a bent 150 degrees geometry to one K(2), one Si(2), and one Si(3) atom. In the tenth O site, O(8) is bonded in a 2-coordinate geometry to one K(1), two equivalent K(2), one Si(2), and one Si(3) atom. is represented by the CIF card [CIF]
data_K2Ca3Si3O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.724
_cell_length_b   7.487
_cell_length_c   12.064
_cell_angle_alpha   85.424
_cell_angle_beta   80.473
_cell_angle_gamma   88.324
_symmetry_Int_Tables_number   1
_cell_volume   508.149
_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
  K  K0  1  0.721  0.960  0.626  1.0
  K  K1  1  0.279  0.040  0.374  1.0
  K  K2  1  0.167  0.939  0.848  1.0
  K  K3  1  0.833  0.061  0.152  1.0
  Ca  Ca4  1  0.207  0.244  0.623  1.0
  Ca  Ca5  1  0.793  0.756  0.377  1.0
  Ca  Ca6  1  0.169  0.470  0.860  1.0
  Ca  Ca7  1  0.831  0.530  0.140  1.0
  Ca  Ca8  1  0.728  0.496  0.660  1.0
  Ca  Ca9  1  0.272  0.504  0.340  1.0
  Si  Si10  1  0.249  0.729  0.578  1.0
  Si  Si11  1  0.751  0.271  0.422  1.0
  Si  Si12  1  0.658  0.185  0.850  1.0
  Si  Si13  1  0.342  0.815  0.150  1.0
  Si  Si14  1  0.364  0.255  0.089  1.0
  Si  Si15  1  0.636  0.745  0.911  1.0
  O  O16  1  0.212  0.933  0.623  1.0
  O  O17  1  0.788  0.067  0.377  1.0
  O  O18  1  0.463  0.311  0.458  1.0
  O  O19  1  0.537  0.689  0.542  1.0
  O  O20  1  0.129  0.570  0.674  1.0
  O  O21  1  0.871  0.430  0.326  1.0
  O  O22  1  0.884  0.285  0.533  1.0
  O  O23  1  0.116  0.715  0.467  1.0
  O  O24  1  0.917  0.262  0.796  1.0
  O  O25  1  0.083  0.738  0.204  1.0
  O  O26  1  0.462  0.250  0.770  1.0
  O  O27  1  0.538  0.750  0.230  1.0
  O  O28  1  0.581  0.249  0.979  1.0
  O  O29  1  0.419  0.751  0.021  1.0
  O  O30  1  0.323  0.038  0.138  1.0
  O  O31  1  0.677  0.962  0.862  1.0
  O  O32  1  0.531  0.646  0.816  1.0
  O  O33  1  0.469  0.354  0.184  1.0
  O  O34  1  0.122  0.333  0.050  1.0
  O  O35  1  0.878  0.667  0.950  1.0
[/CIF]
.
The material structure described by K2Ca3Si3O10 crystallizes in the triclinic P-1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(2), one O(6), one O(8), one O(9), two equivalent O(4), and three equivalent O(1) atoms. In the second K site, K(2) is bonded to one O(1), one O(10), one O(5), one O(6), one O(7), one O(9), and two equivalent O(8) atoms to form distorted KO8 hexagonal bipyramids that share corners with two equivalent K(2)O8 hexagonal bipyramids,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, edges with two equivalent Ca(2)O6 octahedra,  an edgeedge with one Si(3)O4 tetrahedra, edges with two equivalent Si(2)O4 tetrahedra,  a faceface with one Ca(1)O6 octahedra, and  a faceface with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted CaO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra,  a faceface with one K(2)O8 hexagonal bipyramid, and  a faceface with one Ca(2)O6 octahedra. In the second Ca site, Ca(2) is bonded to one O(3), one O(5), one O(6), one O(9), and two equivalent O(10) atoms to form distorted CaO6 octahedra that share  a cornercorner with one K(2)O8 hexagonal bipyramid,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Si(3)O4 tetrahedra, edges with two equivalent K(2)O8 hexagonal bipyramids,  an edgeedge with one Ca(2)O6 octahedra, and  a faceface with one Ca(1)O6 octahedra. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), 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(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one K(2)O8 hexagonal bipyramid,  a cornercorner with one Ca(2)O6 octahedra, and corners with four equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-64°. In the second Si site, Si(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one K(2)O8 hexagonal bipyramid, corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent K(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 20-68°. In the third Si site, Si(3) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with three equivalent Ca(2)O6 octahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one K(2)O8 hexagonal bipyramid, and  a faceface with one K(2)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 50-65°. There are ten inequivalent O sites. In the first O site, O(9) is bonded in a 3-coordinate geometry to one K(1), one K(2), one Ca(2), one Ca(3), and one Si(3) atom. In the second O site, O(10) is bonded in a 4-coordinate geometry to one K(2), two equivalent Ca(2), and one Si(3) atom. In the third O site, O(1) is bonded in a 6-coordinate geometry to one K(2), three equivalent K(1), one Ca(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted trigonal pyramidal geometry to one K(1), one Ca(1), one Ca(3), and one Si(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), and one Si(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent K(1), one Ca(1), one Ca(3), and one Si(1) atom. In the seventh O site, O(5) is bonded in a 5-coordinate geometry to one K(2), one Ca(1), one Ca(2), one Ca(3), and one Si(2) atom. In the eighth O site, O(6) is bonded in a 1-coordinate geometry to one K(1), one K(2), one Ca(1), one Ca(2), one Ca(3), and one Si(2) atom. In the ninth O site, O(7) is bonded in a bent 150 degrees geometry to one K(2), one Si(2), and one Si(3) atom. In the tenth O site, O(8) is bonded in a 2-coordinate geometry to one K(1), two equivalent K(2), one Si(2), and one Si(3) atom. is represented by the CIF card [CIF]
data_K2Ca3Si3O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.724
_cell_length_b   7.487
_cell_length_c   12.064
_cell_angle_alpha   85.424
_cell_angle_beta   80.473
_cell_angle_gamma   88.324
_symmetry_Int_Tables_number   1
_cell_volume   508.149
_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
  K  K0  1  0.721  0.960  0.626  1.0
  K  K1  1  0.279  0.040  0.374  1.0
  K  K2  1  0.167  0.939  0.848  1.0
  K  K3  1  0.833  0.061  0.152  1.0
  Ca  Ca4  1  0.207  0.244  0.623  1.0
  Ca  Ca5  1  0.793  0.756  0.377  1.0
  Ca  Ca6  1  0.169  0.470  0.860  1.0
  Ca  Ca7  1  0.831  0.530  0.140  1.0
  Ca  Ca8  1  0.728  0.496  0.660  1.0
  Ca  Ca9  1  0.272  0.504  0.340  1.0
  Si  Si10  1  0.249  0.729  0.578  1.0
  Si  Si11  1  0.751  0.271  0.422  1.0
  Si  Si12  1  0.658  0.185  0.850  1.0
  Si  Si13  1  0.342  0.815  0.150  1.0
  Si  Si14  1  0.364  0.255  0.089  1.0
  Si  Si15  1  0.636  0.745  0.911  1.0
  O  O16  1  0.212  0.933  0.623  1.0
  O  O17  1  0.788  0.067  0.377  1.0
  O  O18  1  0.463  0.311  0.458  1.0
  O  O19  1  0.537  0.689  0.542  1.0
  O  O20  1  0.129  0.570  0.674  1.0
  O  O21  1  0.871  0.430  0.326  1.0
  O  O22  1  0.884  0.285  0.533  1.0
  O  O23  1  0.116  0.715  0.467  1.0
  O  O24  1  0.917  0.262  0.796  1.0
  O  O25  1  0.083  0.738  0.204  1.0
  O  O26  1  0.462  0.250  0.770  1.0
  O  O27  1  0.538  0.750  0.230  1.0
  O  O28  1  0.581  0.249  0.979  1.0
  O  O29  1  0.419  0.751  0.021  1.0
  O  O30  1  0.323  0.038  0.138  1.0
  O  O31  1  0.677  0.962  0.862  1.0
  O  O32  1  0.531  0.646  0.816  1.0
  O  O33  1  0.469  0.354  0.184  1.0
  O  O34  1  0.122  0.333  0.050  1.0
  O  O35  1  0.878  0.667  0.950  1.0
[/CIF]
.