The structure described by Gd3AsO7 crystallizes in the triclinic P-1 space group. There are three inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(7), two equivalent O(2), and two equivalent O(6) atoms. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(5), one O(6), two equivalent O(4), and two equivalent O(7) atoms. In the third Gd site, Gd(3) is bonded to one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(3) atoms to form distorted GdO7 pentagonal bipyramids that share  a cornercorner with one As(1)O6 octahedra,  a cornercorner with one As(2)O6 octahedra,  an edgeedge with one As(1)O6 octahedra,  an edgeedge with one As(2)O6 octahedra, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 38-43°. There are two inequivalent As sites. In the first As site, As(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form AsO6 octahedra that share corners with two equivalent As(2)O6 octahedra, corners with two equivalent Gd(3)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. In the second As site, As(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form AsO6 octahedra that share corners with two equivalent As(1)O6 octahedra, corners with two equivalent Gd(3)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Gd(2), two equivalent Gd(3), and one As(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one As(1) atom. In the third O site, O(3) is bonded to one Gd(1), two equivalent Gd(3), and one As(1) atom to form distorted OGd3As trigonal pyramids that share  a cornercorner with one O(4)Gd3As tetrahedra,  a cornercorner with one O(7)Gd4 tetrahedra, corners with two equivalent O(6)Gd4 tetrahedra,  a cornercorner with one O(3)Gd3As trigonal pyramid,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(3)Gd3As trigonal pyramid. In the fourth O site, O(4) is bonded to one Gd(1), two equivalent Gd(2), and one As(2) atom to form distorted OGd3As tetrahedra that share  a cornercorner with one O(4)Gd3As tetrahedra, corners with three equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(6)Gd4 tetrahedra,  a cornercorner with one O(3)Gd3As trigonal pyramid,  an edgeedge with one O(4)Gd3As tetrahedra, and  an edgeedge with one O(7)Gd4 tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Gd(2), one Gd(3), one As(1), and one As(2) atom. In the sixth O site, O(6) is bonded to one Gd(2), one Gd(3), and two equivalent Gd(1) atoms to form OGd4 tetrahedra that share corners with three equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(4)Gd3As tetrahedra, corners with two equivalent O(3)Gd3As trigonal pyramids,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(3)Gd3As trigonal pyramid. In the seventh O site, O(7) is bonded to one Gd(1), one Gd(3), and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share corners with three equivalent O(4)Gd3As tetrahedra, corners with three equivalent O(6)Gd4 tetrahedra,  a cornercorner with one O(3)Gd3As trigonal pyramid,  an edgeedge with one O(4)Gd3As tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(3)Gd3As trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Gd3AsO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.362
_cell_length_b   6.453
_cell_length_c   7.502
_cell_angle_alpha   106.638
_cell_angle_beta   89.937
_cell_angle_gamma   98.166
_symmetry_Int_Tables_number   1
_cell_volume   291.802
_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
  Gd  Gd0  1  0.741  0.470  0.121  1.0
  Gd  Gd1  1  0.751  0.504  0.623  1.0
  Gd  Gd2  1  0.542  0.002  0.747  1.0
  Gd  Gd3  1  0.458  0.998  0.253  1.0
  Gd  Gd4  1  0.249  0.496  0.377  1.0
  Gd  Gd5  1  0.259  0.530  0.879  1.0
  As  As6  1  0.000  0.000  0.000  1.0
  As  As7  1  0.000  0.000  0.500  1.0
  O  O8  1  0.724  0.034  0.477  1.0
  O  O9  1  0.927  0.698  0.958  1.0
  O  O10  1  0.723  0.054  0.041  1.0
  O  O11  1  0.940  0.686  0.393  1.0
  O  O12  1  0.914  0.935  0.733  1.0
  O  O13  1  0.567  0.363  0.834  1.0
  O  O14  1  0.559  0.359  0.347  1.0
  O  O15  1  0.441  0.641  0.653  1.0
  O  O16  1  0.433  0.637  0.166  1.0
  O  O17  1  0.086  0.065  0.267  1.0
  O  O18  1  0.060  0.314  0.607  1.0
  O  O19  1  0.277  0.946  0.959  1.0
  O  O20  1  0.073  0.302  0.042  1.0
  O  O21  1  0.276  0.966  0.523  1.0
[/CIF]
.
The structure described by Gd3AsO7 crystallizes in the triclinic P-1 space group. There are three inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(7), two equivalent O(2), and two equivalent O(6) atoms. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(5), one O(6), two equivalent O(4), and two equivalent O(7) atoms. In the third Gd site, Gd(3) is bonded to one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(3) atoms to form distorted GdO7 pentagonal bipyramids that share  a cornercorner with one As(1)O6 octahedra,  a cornercorner with one As(2)O6 octahedra,  an edgeedge with one As(1)O6 octahedra,  an edgeedge with one As(2)O6 octahedra, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 38-43°. There are two inequivalent As sites. In the first As site, As(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form AsO6 octahedra that share corners with two equivalent As(2)O6 octahedra, corners with two equivalent Gd(3)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. In the second As site, As(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form AsO6 octahedra that share corners with two equivalent As(1)O6 octahedra, corners with two equivalent Gd(3)O7 pentagonal bipyramids, and edges with two equivalent Gd(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Gd(2), two equivalent Gd(3), and one As(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one As(1) atom. In the third O site, O(3) is bonded to one Gd(1), two equivalent Gd(3), and one As(1) atom to form distorted OGd3As trigonal pyramids that share  a cornercorner with one O(4)Gd3As tetrahedra,  a cornercorner with one O(7)Gd4 tetrahedra, corners with two equivalent O(6)Gd4 tetrahedra,  a cornercorner with one O(3)Gd3As trigonal pyramid,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(3)Gd3As trigonal pyramid. In the fourth O site, O(4) is bonded to one Gd(1), two equivalent Gd(2), and one As(2) atom to form distorted OGd3As tetrahedra that share  a cornercorner with one O(4)Gd3As tetrahedra, corners with three equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(6)Gd4 tetrahedra,  a cornercorner with one O(3)Gd3As trigonal pyramid,  an edgeedge with one O(4)Gd3As tetrahedra, and  an edgeedge with one O(7)Gd4 tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Gd(2), one Gd(3), one As(1), and one As(2) atom. In the sixth O site, O(6) is bonded to one Gd(2), one Gd(3), and two equivalent Gd(1) atoms to form OGd4 tetrahedra that share corners with three equivalent O(7)Gd4 tetrahedra, corners with four equivalent O(4)Gd3As tetrahedra, corners with two equivalent O(3)Gd3As trigonal pyramids,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(3)Gd3As trigonal pyramid. In the seventh O site, O(7) is bonded to one Gd(1), one Gd(3), and two equivalent Gd(2) atoms to form OGd4 tetrahedra that share corners with three equivalent O(4)Gd3As tetrahedra, corners with three equivalent O(6)Gd4 tetrahedra,  a cornercorner with one O(3)Gd3As trigonal pyramid,  an edgeedge with one O(4)Gd3As tetrahedra,  an edgeedge with one O(6)Gd4 tetrahedra,  an edgeedge with one O(7)Gd4 tetrahedra, and  an edgeedge with one O(3)Gd3As trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Gd3AsO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.362
_cell_length_b   6.453
_cell_length_c   7.502
_cell_angle_alpha   106.638
_cell_angle_beta   89.937
_cell_angle_gamma   98.166
_symmetry_Int_Tables_number   1
_cell_volume   291.802
_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
  Gd  Gd0  1  0.741  0.470  0.121  1.0
  Gd  Gd1  1  0.751  0.504  0.623  1.0
  Gd  Gd2  1  0.542  0.002  0.747  1.0
  Gd  Gd3  1  0.458  0.998  0.253  1.0
  Gd  Gd4  1  0.249  0.496  0.377  1.0
  Gd  Gd5  1  0.259  0.530  0.879  1.0
  As  As6  1  0.000  0.000  0.000  1.0
  As  As7  1  0.000  0.000  0.500  1.0
  O  O8  1  0.724  0.034  0.477  1.0
  O  O9  1  0.927  0.698  0.958  1.0
  O  O10  1  0.723  0.054  0.041  1.0
  O  O11  1  0.940  0.686  0.393  1.0
  O  O12  1  0.914  0.935  0.733  1.0
  O  O13  1  0.567  0.363  0.834  1.0
  O  O14  1  0.559  0.359  0.347  1.0
  O  O15  1  0.441  0.641  0.653  1.0
  O  O16  1  0.433  0.637  0.166  1.0
  O  O17  1  0.086  0.065  0.267  1.0
  O  O18  1  0.060  0.314  0.607  1.0
  O  O19  1  0.277  0.946  0.959  1.0
  O  O20  1  0.073  0.302  0.042  1.0
  O  O21  1  0.276  0.966  0.523  1.0
[/CIF]
.