The material described by GdAlGe2O7 crystallizes in the monoclinic P2_1/c space group. Gd(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(7), two equivalent O(2), and two equivalent O(6) atoms. Al(1) is bonded to one O(1), one O(3), one O(5), one O(6), and one O(7) atom to form AlO5 trigonal bipyramids that share corners with two equivalent Ge(1)O4 tetrahedra and corners with three equivalent Ge(2)O4 tetrahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(2)O4 tetrahedra and corners with two equivalent Al(1)O5 trigonal bipyramids. In the second Ge site, Ge(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(1)O4 tetrahedra and corners with three equivalent Al(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted trigonal planar geometry to one Gd(1), one Al(1), and one Ge(1) atom. In the second O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Gd(1), one Al(1), and one Ge(1) atom. In the third O site, O(7) is bonded in a 2-coordinate geometry to one Gd(1), one Al(1), and one Ge(2) atom. In the fourth O site, O(1) is bonded in a distorted trigonal planar geometry to one Gd(1), one Al(1), and one Ge(2) atom. In the fifth O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one Ge(1) atom. In the sixth O site, O(3) is bonded in a distorted trigonal planar geometry to one Gd(1), one Al(1), and one Ge(2) atom. In the seventh O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Gd(1), one Ge(1), and one Ge(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_GdAlGe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.552
_cell_length_b   7.261
_cell_length_c   12.773
_cell_angle_alpha   62.445
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   538.707
_cell_formula_units_Z   4
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
  Gd  Gd0  1  0.354  0.742  0.528  1.0
  Gd  Gd1  1  0.646  0.258  0.472  1.0
  Gd  Gd2  1  0.854  0.258  0.972  1.0
  Gd  Gd3  1  0.146  0.742  0.028  1.0
  Al  Al4  1  0.398  0.712  0.271  1.0
  Al  Al5  1  0.602  0.288  0.729  1.0
  Al  Al6  1  0.898  0.288  0.229  1.0
  Al  Al7  1  0.102  0.712  0.771  1.0
  Ge  Ge8  1  0.657  0.711  0.048  1.0
  Ge  Ge9  1  0.343  0.289  0.952  1.0
  Ge  Ge10  1  0.157  0.289  0.452  1.0
  Ge  Ge11  1  0.843  0.711  0.548  1.0
  Ge  Ge12  1  0.910  0.803  0.280  1.0
  Ge  Ge13  1  0.090  0.197  0.720  1.0
  Ge  Ge14  1  0.410  0.197  0.220  1.0
  Ge  Ge15  1  0.590  0.803  0.780  1.0
  O  O16  1  0.376  0.926  0.305  1.0
  O  O17  1  0.624  0.074  0.695  1.0
  O  O18  1  0.876  0.074  0.195  1.0
  O  O19  1  0.124  0.926  0.805  1.0
  O  O20  1  0.827  0.910  0.023  1.0
  O  O21  1  0.173  0.090  0.977  1.0
  O  O22  1  0.327  0.090  0.477  1.0
  O  O23  1  0.673  0.910  0.523  1.0
  O  O24  1  0.616  0.277  0.279  1.0
  O  O25  1  0.384  0.723  0.721  1.0
  O  O26  1  0.116  0.723  0.221  1.0
  O  O27  1  0.884  0.277  0.779  1.0
  O  O28  1  0.001  0.748  0.426  1.0
  O  O29  1  0.999  0.252  0.574  1.0
  O  O30  1  0.501  0.252  0.074  1.0
  O  O31  1  0.499  0.748  0.926  1.0
  O  O32  1  0.445  0.705  0.134  1.0
  O  O33  1  0.555  0.295  0.866  1.0
  O  O34  1  0.945  0.295  0.366  1.0
  O  O35  1  0.055  0.705  0.634  1.0
  O  O36  1  0.843  0.509  0.084  1.0
  O  O37  1  0.157  0.491  0.916  1.0
  O  O38  1  0.343  0.491  0.416  1.0
  O  O39  1  0.657  0.509  0.584  1.0
  O  O40  1  0.682  0.658  0.313  1.0
  O  O41  1  0.318  0.342  0.687  1.0
  O  O42  1  0.182  0.342  0.187  1.0
  O  O43  1  0.818  0.658  0.813  1.0
[/CIF]
.
The material described by GdAlGe2O7 crystallizes in the monoclinic P2_1/c space group. Gd(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(7), two equivalent O(2), and two equivalent O(6) atoms. Al(1) is bonded to one O(1), one O(3), one O(5), one O(6), and one O(7) atom to form AlO5 trigonal bipyramids that share corners with two equivalent Ge(1)O4 tetrahedra and corners with three equivalent Ge(2)O4 tetrahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(2)O4 tetrahedra and corners with two equivalent Al(1)O5 trigonal bipyramids. In the second Ge site, Ge(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form GeO4 tetrahedra that share  a cornercorner with one Ge(1)O4 tetrahedra and corners with three equivalent Al(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted trigonal planar geometry to one Gd(1), one Al(1), and one Ge(1) atom. In the second O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Gd(1), one Al(1), and one Ge(1) atom. In the third O site, O(7) is bonded in a 2-coordinate geometry to one Gd(1), one Al(1), and one Ge(2) atom. In the fourth O site, O(1) is bonded in a distorted trigonal planar geometry to one Gd(1), one Al(1), and one Ge(2) atom. In the fifth O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one Ge(1) atom. In the sixth O site, O(3) is bonded in a distorted trigonal planar geometry to one Gd(1), one Al(1), and one Ge(2) atom. In the seventh O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Gd(1), one Ge(1), and one Ge(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_GdAlGe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.552
_cell_length_b   7.261
_cell_length_c   12.773
_cell_angle_alpha   62.445
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   538.707
_cell_formula_units_Z   4
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
  Gd  Gd0  1  0.354  0.742  0.528  1.0
  Gd  Gd1  1  0.646  0.258  0.472  1.0
  Gd  Gd2  1  0.854  0.258  0.972  1.0
  Gd  Gd3  1  0.146  0.742  0.028  1.0
  Al  Al4  1  0.398  0.712  0.271  1.0
  Al  Al5  1  0.602  0.288  0.729  1.0
  Al  Al6  1  0.898  0.288  0.229  1.0
  Al  Al7  1  0.102  0.712  0.771  1.0
  Ge  Ge8  1  0.657  0.711  0.048  1.0
  Ge  Ge9  1  0.343  0.289  0.952  1.0
  Ge  Ge10  1  0.157  0.289  0.452  1.0
  Ge  Ge11  1  0.843  0.711  0.548  1.0
  Ge  Ge12  1  0.910  0.803  0.280  1.0
  Ge  Ge13  1  0.090  0.197  0.720  1.0
  Ge  Ge14  1  0.410  0.197  0.220  1.0
  Ge  Ge15  1  0.590  0.803  0.780  1.0
  O  O16  1  0.376  0.926  0.305  1.0
  O  O17  1  0.624  0.074  0.695  1.0
  O  O18  1  0.876  0.074  0.195  1.0
  O  O19  1  0.124  0.926  0.805  1.0
  O  O20  1  0.827  0.910  0.023  1.0
  O  O21  1  0.173  0.090  0.977  1.0
  O  O22  1  0.327  0.090  0.477  1.0
  O  O23  1  0.673  0.910  0.523  1.0
  O  O24  1  0.616  0.277  0.279  1.0
  O  O25  1  0.384  0.723  0.721  1.0
  O  O26  1  0.116  0.723  0.221  1.0
  O  O27  1  0.884  0.277  0.779  1.0
  O  O28  1  0.001  0.748  0.426  1.0
  O  O29  1  0.999  0.252  0.574  1.0
  O  O30  1  0.501  0.252  0.074  1.0
  O  O31  1  0.499  0.748  0.926  1.0
  O  O32  1  0.445  0.705  0.134  1.0
  O  O33  1  0.555  0.295  0.866  1.0
  O  O34  1  0.945  0.295  0.366  1.0
  O  O35  1  0.055  0.705  0.634  1.0
  O  O36  1  0.843  0.509  0.084  1.0
  O  O37  1  0.157  0.491  0.916  1.0
  O  O38  1  0.343  0.491  0.416  1.0
  O  O39  1  0.657  0.509  0.584  1.0
  O  O40  1  0.682  0.658  0.313  1.0
  O  O41  1  0.318  0.342  0.687  1.0
  O  O42  1  0.182  0.342  0.187  1.0
  O  O43  1  0.818  0.658  0.813  1.0
[/CIF]
.