The material structure described by Mg3Y7Ge8 crystallizes in the monoclinic P2_1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one Ge(2), one Ge(3), one Ge(7), and two equivalent Ge(5) atoms to form distorted corner-sharing MgGe5 square pyramids. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to one Ge(1), one Ge(4), one Ge(8), and two equivalent Ge(6) atoms. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(5), and two equivalent Ge(7) atoms. There are seven inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(4), one Ge(7), and two equivalent Ge(5) atoms. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(4), one Ge(8), and two equivalent Ge(6) atoms. In the third Y site, Y(3) is bonded in a 7-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(4), one Ge(8), and two equivalent Ge(6) atoms. In the fourth Y site, Y(4) is bonded in a 7-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(4), one Ge(7), and two equivalent Ge(5) atoms. In the fifth Y site, Y(5) is bonded in a 6-coordinate geometry to one Ge(1), one Ge(2), one Ge(4), one Ge(6), and two equivalent Ge(8) atoms. In the sixth Y site, Y(6) is bonded in a 6-coordinate geometry to one Ge(1), one Ge(3), one Ge(4), one Ge(6), and two equivalent Ge(8) atoms. In the seventh Y site, Y(7) is bonded in a 6-coordinate geometry to one Ge(2), one Ge(3), one Ge(4), one Ge(5), and two equivalent Ge(7) atoms. There are eight inequivalent Ge sites. In the first Ge site, Ge(7) is bonded in a 8-coordinate geometry to one Mg(1), two equivalent Mg(3), one Y(1), one Y(4), two equivalent Y(7), and one Ge(5) atom. In the second Ge site, Ge(8) is bonded in a 8-coordinate geometry to one Mg(2), one Y(2), one Y(3), two equivalent Y(5), two equivalent Y(6), and one Ge(6) atom. In the third Ge site, Ge(1) is bonded in a 9-coordinate geometry to one Mg(2), one Mg(3), one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(6), and one Ge(3) atom. In the fourth Ge site, Ge(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(3), one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(7), and one Ge(4) atom. In the fifth Ge site, Ge(3) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(3), one Y(1), one Y(2), one Y(3), one Y(4), one Y(6), one Y(7), and one Ge(1) atom. In the sixth Ge site, Ge(4) is bonded in a 9-coordinate geometry to one Mg(2), one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(6), one Y(7), and one Ge(2) atom. In the seventh Ge site, Ge(5) is bonded in a 9-coordinate geometry to one Mg(3), two equivalent Mg(1), one Y(7), two equivalent Y(1), two equivalent Y(4), and one Ge(7) atom. In the eighth Ge site, Ge(6) is bonded in a 9-coordinate geometry to two equivalent Mg(2), one Y(5), one Y(6), two equivalent Y(2), two equivalent Y(3), and one Ge(8) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y7Mg3Ge8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.163
_cell_length_b   7.825
_cell_length_c   14.474
_cell_angle_alpha   89.997
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   811.298
_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
  Y  Y0  1  0.509  0.934  0.847  1.0
  Y  Y1  1  0.009  0.066  0.153  1.0
  Y  Y2  1  0.487  0.567  0.345  1.0
  Y  Y3  1  0.987  0.433  0.655  1.0
  Y  Y4  1  0.490  0.566  0.657  1.0
  Y  Y5  1  0.990  0.434  0.343  1.0
  Y  Y6  1  0.511  0.935  0.152  1.0
  Y  Y7  1  0.011  0.065  0.848  1.0
  Y  Y8  1  0.329  0.073  0.375  1.0
  Y  Y9  1  0.829  0.927  0.625  1.0
  Y  Y10  1  0.331  0.075  0.624  1.0
  Y  Y11  1  0.831  0.925  0.376  1.0
  Y  Y12  1  0.669  0.431  0.121  1.0
  Y  Y13  1  0.169  0.569  0.879  1.0
  Mg  Mg14  1  0.842  0.764  0.001  1.0
  Mg  Mg15  1  0.342  0.236  0.999  1.0
  Mg  Mg16  1  0.161  0.732  0.500  1.0
  Mg  Mg17  1  0.661  0.268  0.500  1.0
  Mg  Mg18  1  0.673  0.426  0.874  1.0
  Mg  Mg19  1  0.173  0.574  0.126  1.0
  Ge  Ge20  1  0.669  0.218  0.716  1.0
  Ge  Ge21  1  0.169  0.782  0.284  1.0
  Ge  Ge22  1  0.328  0.287  0.210  1.0
  Ge  Ge23  1  0.828  0.713  0.790  1.0
  Ge  Ge24  1  0.334  0.285  0.788  1.0
  Ge  Ge25  1  0.834  0.715  0.212  1.0
  Ge  Ge26  1  0.670  0.217  0.285  1.0
  Ge  Ge27  1  0.170  0.783  0.715  1.0
  Ge  Ge28  1  0.714  0.112  0.000  1.0
  Ge  Ge29  1  0.214  0.888  1.000  1.0
  Ge  Ge30  1  0.288  0.387  0.500  1.0
  Ge  Ge31  1  0.788  0.613  0.500  1.0
  Ge  Ge32  1  0.471  0.656  0.001  1.0
  Ge  Ge33  1  0.971  0.344  0.999  1.0
  Ge  Ge34  1  0.523  0.839  0.501  1.0
  Ge  Ge35  1  0.023  0.161  0.499  1.0
[/CIF]
.
The material structure described by Mg3Y7Ge8 crystallizes in the monoclinic P2_1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one Ge(2), one Ge(3), one Ge(7), and two equivalent Ge(5) atoms to form distorted corner-sharing MgGe5 square pyramids. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to one Ge(1), one Ge(4), one Ge(8), and two equivalent Ge(6) atoms. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(5), and two equivalent Ge(7) atoms. There are seven inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(4), one Ge(7), and two equivalent Ge(5) atoms. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(4), one Ge(8), and two equivalent Ge(6) atoms. In the third Y site, Y(3) is bonded in a 7-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(4), one Ge(8), and two equivalent Ge(6) atoms. In the fourth Y site, Y(4) is bonded in a 7-coordinate geometry to one Ge(1), one Ge(2), one Ge(3), one Ge(4), one Ge(7), and two equivalent Ge(5) atoms. In the fifth Y site, Y(5) is bonded in a 6-coordinate geometry to one Ge(1), one Ge(2), one Ge(4), one Ge(6), and two equivalent Ge(8) atoms. In the sixth Y site, Y(6) is bonded in a 6-coordinate geometry to one Ge(1), one Ge(3), one Ge(4), one Ge(6), and two equivalent Ge(8) atoms. In the seventh Y site, Y(7) is bonded in a 6-coordinate geometry to one Ge(2), one Ge(3), one Ge(4), one Ge(5), and two equivalent Ge(7) atoms. There are eight inequivalent Ge sites. In the first Ge site, Ge(7) is bonded in a 8-coordinate geometry to one Mg(1), two equivalent Mg(3), one Y(1), one Y(4), two equivalent Y(7), and one Ge(5) atom. In the second Ge site, Ge(8) is bonded in a 8-coordinate geometry to one Mg(2), one Y(2), one Y(3), two equivalent Y(5), two equivalent Y(6), and one Ge(6) atom. In the third Ge site, Ge(1) is bonded in a 9-coordinate geometry to one Mg(2), one Mg(3), one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(6), and one Ge(3) atom. In the fourth Ge site, Ge(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(3), one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(7), and one Ge(4) atom. In the fifth Ge site, Ge(3) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(3), one Y(1), one Y(2), one Y(3), one Y(4), one Y(6), one Y(7), and one Ge(1) atom. In the sixth Ge site, Ge(4) is bonded in a 9-coordinate geometry to one Mg(2), one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(6), one Y(7), and one Ge(2) atom. In the seventh Ge site, Ge(5) is bonded in a 9-coordinate geometry to one Mg(3), two equivalent Mg(1), one Y(7), two equivalent Y(1), two equivalent Y(4), and one Ge(7) atom. In the eighth Ge site, Ge(6) is bonded in a 9-coordinate geometry to two equivalent Mg(2), one Y(5), one Y(6), two equivalent Y(2), two equivalent Y(3), and one Ge(8) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y7Mg3Ge8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.163
_cell_length_b   7.825
_cell_length_c   14.474
_cell_angle_alpha   89.997
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   811.298
_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
  Y  Y0  1  0.509  0.934  0.847  1.0
  Y  Y1  1  0.009  0.066  0.153  1.0
  Y  Y2  1  0.487  0.567  0.345  1.0
  Y  Y3  1  0.987  0.433  0.655  1.0
  Y  Y4  1  0.490  0.566  0.657  1.0
  Y  Y5  1  0.990  0.434  0.343  1.0
  Y  Y6  1  0.511  0.935  0.152  1.0
  Y  Y7  1  0.011  0.065  0.848  1.0
  Y  Y8  1  0.329  0.073  0.375  1.0
  Y  Y9  1  0.829  0.927  0.625  1.0
  Y  Y10  1  0.331  0.075  0.624  1.0
  Y  Y11  1  0.831  0.925  0.376  1.0
  Y  Y12  1  0.669  0.431  0.121  1.0
  Y  Y13  1  0.169  0.569  0.879  1.0
  Mg  Mg14  1  0.842  0.764  0.001  1.0
  Mg  Mg15  1  0.342  0.236  0.999  1.0
  Mg  Mg16  1  0.161  0.732  0.500  1.0
  Mg  Mg17  1  0.661  0.268  0.500  1.0
  Mg  Mg18  1  0.673  0.426  0.874  1.0
  Mg  Mg19  1  0.173  0.574  0.126  1.0
  Ge  Ge20  1  0.669  0.218  0.716  1.0
  Ge  Ge21  1  0.169  0.782  0.284  1.0
  Ge  Ge22  1  0.328  0.287  0.210  1.0
  Ge  Ge23  1  0.828  0.713  0.790  1.0
  Ge  Ge24  1  0.334  0.285  0.788  1.0
  Ge  Ge25  1  0.834  0.715  0.212  1.0
  Ge  Ge26  1  0.670  0.217  0.285  1.0
  Ge  Ge27  1  0.170  0.783  0.715  1.0
  Ge  Ge28  1  0.714  0.112  0.000  1.0
  Ge  Ge29  1  0.214  0.888  1.000  1.0
  Ge  Ge30  1  0.288  0.387  0.500  1.0
  Ge  Ge31  1  0.788  0.613  0.500  1.0
  Ge  Ge32  1  0.471  0.656  0.001  1.0
  Ge  Ge33  1  0.971  0.344  0.999  1.0
  Ge  Ge34  1  0.523  0.839  0.501  1.0
  Ge  Ge35  1  0.023  0.161  0.499  1.0
[/CIF]
.