The material structure described by Ca2Ge7O16 crystallizes in the tetragonal P-4b2 space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form GeO4 tetrahedra that share corners with two equivalent Ge(2)O6 octahedra and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-61°. In the second Ge site, Ge(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing GeO6 octahedra. In the third Ge site, Ge(3) is bonded to four equivalent O(3) atoms to form corner-sharing GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ge(1), and one Ge(2) atom. In the second O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and two equivalent Ge(1) atoms. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ge(1), and one Ge(2) atom. In the fourth O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ge(2), and one Ge(3) atom. is represented by the CIF card [CIF]
data_Ca2Ge7O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.385
_cell_length_b   11.385
_cell_length_c   4.658
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   603.775
_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  0.835  0.335  0.500  1.0
  Ca  Ca1  1  0.165  0.665  0.500  1.0
  Ca  Ca2  1  0.335  0.165  0.500  1.0
  Ca  Ca3  1  0.665  0.835  0.500  1.0
  Ge  Ge4  1  0.566  0.312  0.990  1.0
  Ge  Ge5  1  0.434  0.688  0.990  1.0
  Ge  Ge6  1  0.066  0.188  0.990  1.0
  Ge  Ge7  1  0.934  0.812  0.990  1.0
  Ge  Ge8  1  0.812  0.066  0.010  1.0
  Ge  Ge9  1  0.188  0.934  0.010  1.0
  Ge  Ge10  1  0.312  0.434  0.010  1.0
  Ge  Ge11  1  0.688  0.566  0.010  1.0
  Ge  Ge12  1  0.634  0.134  0.500  1.0
  Ge  Ge13  1  0.366  0.866  0.500  1.0
  Ge  Ge14  1  0.134  0.366  0.500  1.0
  Ge  Ge15  1  0.866  0.634  0.500  1.0
  Ge  Ge16  1  0.500  0.000  0.000  1.0
  Ge  Ge17  1  0.000  0.500  0.000  1.0
  O  O18  1  0.640  0.432  0.161  1.0
  O  O19  1  0.360  0.568  0.161  1.0
  O  O20  1  0.140  0.068  0.161  1.0
  O  O21  1  0.860  0.932  0.161  1.0
  O  O22  1  0.932  0.140  0.839  1.0
  O  O23  1  0.068  0.860  0.839  1.0
  O  O24  1  0.432  0.360  0.839  1.0
  O  O25  1  0.568  0.640  0.839  1.0
  O  O26  1  0.527  0.219  0.276  1.0
  O  O27  1  0.473  0.781  0.276  1.0
  O  O28  1  0.027  0.281  0.276  1.0
  O  O29  1  0.973  0.719  0.276  1.0
  O  O30  1  0.501  0.117  0.752  1.0
  O  O31  1  0.499  0.883  0.752  1.0
  O  O32  1  0.001  0.383  0.752  1.0
  O  O33  1  0.999  0.617  0.752  1.0
  O  O34  1  0.670  0.265  0.731  1.0
  O  O35  1  0.330  0.735  0.731  1.0
  O  O36  1  0.883  0.501  0.248  1.0
  O  O37  1  0.117  0.499  0.248  1.0
  O  O38  1  0.383  0.999  0.248  1.0
  O  O39  1  0.617  0.001  0.248  1.0
  O  O40  1  0.781  0.527  0.724  1.0
  O  O41  1  0.219  0.473  0.724  1.0
  O  O42  1  0.281  0.973  0.724  1.0
  O  O43  1  0.719  0.027  0.724  1.0
  O  O44  1  0.735  0.670  0.269  1.0
  O  O45  1  0.265  0.330  0.269  1.0
  O  O46  1  0.235  0.830  0.269  1.0
  O  O47  1  0.765  0.170  0.269  1.0
  O  O48  1  0.830  0.765  0.731  1.0
  O  O49  1  0.170  0.235  0.731  1.0
[/CIF]
.
The material structure described by Ca2Ge7O16 crystallizes in the tetragonal P-4b2 space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form GeO4 tetrahedra that share corners with two equivalent Ge(2)O6 octahedra and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-61°. In the second Ge site, Ge(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing GeO6 octahedra. In the third Ge site, Ge(3) is bonded to four equivalent O(3) atoms to form corner-sharing GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ge(1), and one Ge(2) atom. In the second O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and two equivalent Ge(1) atoms. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ge(1), and one Ge(2) atom. In the fourth O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ge(2), and one Ge(3) atom. is represented by the CIF card [CIF]
data_Ca2Ge7O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.385
_cell_length_b   11.385
_cell_length_c   4.658
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   603.775
_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  0.835  0.335  0.500  1.0
  Ca  Ca1  1  0.165  0.665  0.500  1.0
  Ca  Ca2  1  0.335  0.165  0.500  1.0
  Ca  Ca3  1  0.665  0.835  0.500  1.0
  Ge  Ge4  1  0.566  0.312  0.990  1.0
  Ge  Ge5  1  0.434  0.688  0.990  1.0
  Ge  Ge6  1  0.066  0.188  0.990  1.0
  Ge  Ge7  1  0.934  0.812  0.990  1.0
  Ge  Ge8  1  0.812  0.066  0.010  1.0
  Ge  Ge9  1  0.188  0.934  0.010  1.0
  Ge  Ge10  1  0.312  0.434  0.010  1.0
  Ge  Ge11  1  0.688  0.566  0.010  1.0
  Ge  Ge12  1  0.634  0.134  0.500  1.0
  Ge  Ge13  1  0.366  0.866  0.500  1.0
  Ge  Ge14  1  0.134  0.366  0.500  1.0
  Ge  Ge15  1  0.866  0.634  0.500  1.0
  Ge  Ge16  1  0.500  0.000  0.000  1.0
  Ge  Ge17  1  0.000  0.500  0.000  1.0
  O  O18  1  0.640  0.432  0.161  1.0
  O  O19  1  0.360  0.568  0.161  1.0
  O  O20  1  0.140  0.068  0.161  1.0
  O  O21  1  0.860  0.932  0.161  1.0
  O  O22  1  0.932  0.140  0.839  1.0
  O  O23  1  0.068  0.860  0.839  1.0
  O  O24  1  0.432  0.360  0.839  1.0
  O  O25  1  0.568  0.640  0.839  1.0
  O  O26  1  0.527  0.219  0.276  1.0
  O  O27  1  0.473  0.781  0.276  1.0
  O  O28  1  0.027  0.281  0.276  1.0
  O  O29  1  0.973  0.719  0.276  1.0
  O  O30  1  0.501  0.117  0.752  1.0
  O  O31  1  0.499  0.883  0.752  1.0
  O  O32  1  0.001  0.383  0.752  1.0
  O  O33  1  0.999  0.617  0.752  1.0
  O  O34  1  0.670  0.265  0.731  1.0
  O  O35  1  0.330  0.735  0.731  1.0
  O  O36  1  0.883  0.501  0.248  1.0
  O  O37  1  0.117  0.499  0.248  1.0
  O  O38  1  0.383  0.999  0.248  1.0
  O  O39  1  0.617  0.001  0.248  1.0
  O  O40  1  0.781  0.527  0.724  1.0
  O  O41  1  0.219  0.473  0.724  1.0
  O  O42  1  0.281  0.973  0.724  1.0
  O  O43  1  0.719  0.027  0.724  1.0
  O  O44  1  0.735  0.670  0.269  1.0
  O  O45  1  0.265  0.330  0.269  1.0
  O  O46  1  0.235  0.830  0.269  1.0
  O  O47  1  0.765  0.170  0.269  1.0
  O  O48  1  0.830  0.765  0.731  1.0
  O  O49  1  0.170  0.235  0.731  1.0
[/CIF]
.