The material structure described by Ca3Ge4 crystallizes in the hexagonal P6_3/m space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one Ge(4), two equivalent Ge(2), two equivalent Ge(3), and four equivalent Ge(1) atoms. In the second Ca site, Ca(2) is bonded in a 11-coordinate geometry to two equivalent Ge(3), three equivalent Ge(2), and six equivalent Ge(1) atoms. In the third Ca site, Ca(3) is bonded in an octahedral geometry to six equivalent Ge(1) atoms. In the fourth Ca site, Ca(4) is bonded in a distorted trigonal planar geometry to three equivalent Ge(2) and six equivalent Ge(1) atoms. There are four inequivalent Ge sites. In the first Ge site, Ge(3) is bonded in a 10-coordinate geometry to one Ca(2), six equivalent Ca(1), and three equivalent Ge(1) atoms. In the second Ge site, Ge(4) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three equivalent Ge(2) atoms. In the third Ge site, Ge(1) is bonded in a 9-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), four equivalent Ca(1), one Ge(2), and one Ge(3) atom. In the fourth Ge site, Ge(2) is bonded in a 9-coordinate geometry to one Ca(2), one Ca(4), four equivalent Ca(1), one Ge(4), and two equivalent Ge(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Ge4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.789
_cell_length_b   8.789
_cell_length_c   15.284
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   1022.499
_cell_formula_units_Z   6
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  0.091  0.665  0.600  1.0
  Ca  Ca1  1  0.335  0.426  0.600  1.0
  Ca  Ca2  1  0.574  0.909  0.600  1.0
  Ca  Ca3  1  0.909  0.335  0.100  1.0
  Ca  Ca4  1  0.665  0.574  0.100  1.0
  Ca  Ca5  1  0.426  0.091  0.100  1.0
  Ca  Ca6  1  0.909  0.335  0.400  1.0
  Ca  Ca7  1  0.665  0.574  0.400  1.0
  Ca  Ca8  1  0.426  0.091  0.400  1.0
  Ca  Ca9  1  0.091  0.665  0.900  1.0
  Ca  Ca10  1  0.335  0.426  0.900  1.0
  Ca  Ca11  1  0.574  0.909  0.900  1.0
  Ca  Ca12  1  0.667  0.333  0.750  1.0
  Ca  Ca13  1  0.333  0.667  0.250  1.0
  Ca  Ca14  1  0.000  0.000  0.500  1.0
  Ca  Ca15  1  0.000  0.000  0.000  1.0
  Ca  Ca16  1  0.000  0.000  0.750  1.0
  Ca  Ca17  1  0.000  0.000  0.250  1.0
  Ge  Ge18  1  0.744  0.655  0.604  1.0
  Ge  Ge19  1  0.345  0.089  0.604  1.0
  Ge  Ge20  1  0.911  0.256  0.604  1.0
  Ge  Ge21  1  0.256  0.345  0.104  1.0
  Ge  Ge22  1  0.655  0.911  0.104  1.0
  Ge  Ge23  1  0.089  0.744  0.104  1.0
  Ge  Ge24  1  0.256  0.345  0.396  1.0
  Ge  Ge25  1  0.655  0.911  0.396  1.0
  Ge  Ge26  1  0.089  0.744  0.396  1.0
  Ge  Ge27  1  0.744  0.655  0.896  1.0
  Ge  Ge28  1  0.345  0.089  0.896  1.0
  Ge  Ge29  1  0.911  0.256  0.896  1.0
  Ge  Ge30  1  0.312  0.944  0.750  1.0
  Ge  Ge31  1  0.056  0.368  0.750  1.0
  Ge  Ge32  1  0.632  0.688  0.750  1.0
  Ge  Ge33  1  0.688  0.056  0.250  1.0
  Ge  Ge34  1  0.944  0.632  0.250  1.0
  Ge  Ge35  1  0.368  0.312  0.250  1.0
  Ge  Ge36  1  0.667  0.333  0.551  1.0
  Ge  Ge37  1  0.333  0.667  0.051  1.0
  Ge  Ge38  1  0.333  0.667  0.449  1.0
  Ge  Ge39  1  0.667  0.333  0.949  1.0
  Ge  Ge40  1  0.333  0.667  0.750  1.0
  Ge  Ge41  1  0.667  0.333  0.250  1.0
[/CIF]
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The material structure described by Ca3Ge4 crystallizes in the hexagonal P6_3/m space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one Ge(4), two equivalent Ge(2), two equivalent Ge(3), and four equivalent Ge(1) atoms. In the second Ca site, Ca(2) is bonded in a 11-coordinate geometry to two equivalent Ge(3), three equivalent Ge(2), and six equivalent Ge(1) atoms. In the third Ca site, Ca(3) is bonded in an octahedral geometry to six equivalent Ge(1) atoms. In the fourth Ca site, Ca(4) is bonded in a distorted trigonal planar geometry to three equivalent Ge(2) and six equivalent Ge(1) atoms. There are four inequivalent Ge sites. In the first Ge site, Ge(3) is bonded in a 10-coordinate geometry to one Ca(2), six equivalent Ca(1), and three equivalent Ge(1) atoms. In the second Ge site, Ge(4) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three equivalent Ge(2) atoms. In the third Ge site, Ge(1) is bonded in a 9-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), four equivalent Ca(1), one Ge(2), and one Ge(3) atom. In the fourth Ge site, Ge(2) is bonded in a 9-coordinate geometry to one Ca(2), one Ca(4), four equivalent Ca(1), one Ge(4), and two equivalent Ge(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Ge4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.789
_cell_length_b   8.789
_cell_length_c   15.284
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   1022.499
_cell_formula_units_Z   6
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  0.091  0.665  0.600  1.0
  Ca  Ca1  1  0.335  0.426  0.600  1.0
  Ca  Ca2  1  0.574  0.909  0.600  1.0
  Ca  Ca3  1  0.909  0.335  0.100  1.0
  Ca  Ca4  1  0.665  0.574  0.100  1.0
  Ca  Ca5  1  0.426  0.091  0.100  1.0
  Ca  Ca6  1  0.909  0.335  0.400  1.0
  Ca  Ca7  1  0.665  0.574  0.400  1.0
  Ca  Ca8  1  0.426  0.091  0.400  1.0
  Ca  Ca9  1  0.091  0.665  0.900  1.0
  Ca  Ca10  1  0.335  0.426  0.900  1.0
  Ca  Ca11  1  0.574  0.909  0.900  1.0
  Ca  Ca12  1  0.667  0.333  0.750  1.0
  Ca  Ca13  1  0.333  0.667  0.250  1.0
  Ca  Ca14  1  0.000  0.000  0.500  1.0
  Ca  Ca15  1  0.000  0.000  0.000  1.0
  Ca  Ca16  1  0.000  0.000  0.750  1.0
  Ca  Ca17  1  0.000  0.000  0.250  1.0
  Ge  Ge18  1  0.744  0.655  0.604  1.0
  Ge  Ge19  1  0.345  0.089  0.604  1.0
  Ge  Ge20  1  0.911  0.256  0.604  1.0
  Ge  Ge21  1  0.256  0.345  0.104  1.0
  Ge  Ge22  1  0.655  0.911  0.104  1.0
  Ge  Ge23  1  0.089  0.744  0.104  1.0
  Ge  Ge24  1  0.256  0.345  0.396  1.0
  Ge  Ge25  1  0.655  0.911  0.396  1.0
  Ge  Ge26  1  0.089  0.744  0.396  1.0
  Ge  Ge27  1  0.744  0.655  0.896  1.0
  Ge  Ge28  1  0.345  0.089  0.896  1.0
  Ge  Ge29  1  0.911  0.256  0.896  1.0
  Ge  Ge30  1  0.312  0.944  0.750  1.0
  Ge  Ge31  1  0.056  0.368  0.750  1.0
  Ge  Ge32  1  0.632  0.688  0.750  1.0
  Ge  Ge33  1  0.688  0.056  0.250  1.0
  Ge  Ge34  1  0.944  0.632  0.250  1.0
  Ge  Ge35  1  0.368  0.312  0.250  1.0
  Ge  Ge36  1  0.667  0.333  0.551  1.0
  Ge  Ge37  1  0.333  0.667  0.051  1.0
  Ge  Ge38  1  0.333  0.667  0.449  1.0
  Ge  Ge39  1  0.667  0.333  0.949  1.0
  Ge  Ge40  1  0.333  0.667  0.750  1.0
  Ge  Ge41  1  0.667  0.333  0.250  1.0
[/CIF]
.