The material described by Sm3TaO7 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to one O(1), one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form distorted SmO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Sm(1)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Sm(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 39-49°. In the second Sm site, Sm(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Ta(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Sm(1)O7 pentagonal bipyramids, and edges with four equivalent Sm(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(1) and two equivalent Ta(1) atoms to form distorted OSm2Ta2 trigonal pyramids that share corners with two equivalent O(4)Sm4 tetrahedra, corners with four equivalent O(5)Sm3Ta tetrahedra, corners with two equivalent O(1)Sm2Ta2 trigonal pyramids,  an edgeedge with one O(2)Sm4 tetrahedra, and edges with two equivalent O(5)Sm3Ta tetrahedra. In the second O site, O(2) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(2)Sm4 tetrahedra, corners with four equivalent O(5)Sm3Ta tetrahedra, corners with four equivalent O(4)Sm4 tetrahedra,  an edgeedge with one O(4)Sm4 tetrahedra, edges with two equivalent O(5)Sm3Ta tetrahedra, and  an edgeedge with one O(1)Sm2Ta2 trigonal pyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sm(2), two equivalent Sm(1), and one Ta(1) atom. In the fourth O site, O(4) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(4)Sm4 tetrahedra, corners with four equivalent O(5)Sm3Ta tetrahedra, corners with four equivalent O(2)Sm4 tetrahedra, corners with two equivalent O(1)Sm2Ta2 trigonal pyramids,  an edgeedge with one O(2)Sm4 tetrahedra, and edges with two equivalent O(5)Sm3Ta tetrahedra. In the fifth O site, O(5) is bonded to one Sm(2), two equivalent Sm(1), and one Ta(1) atom to form distorted OSm3Ta tetrahedra that share corners with two equivalent O(5)Sm3Ta tetrahedra, corners with two equivalent O(2)Sm4 tetrahedra, corners with two equivalent O(4)Sm4 tetrahedra, corners with two equivalent O(1)Sm2Ta2 trigonal pyramids,  an edgeedge with one O(5)Sm3Ta tetrahedra,  an edgeedge with one O(2)Sm4 tetrahedra,  an edgeedge with one O(4)Sm4 tetrahedra, and  an edgeedge with one O(1)Sm2Ta2 trigonal pyramid. is represented by the CIF file [CIF]
data_Sm3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.587
_cell_length_b   6.587
_cell_length_c   7.579
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   108.948
_symmetry_Int_Tables_number   1
_cell_volume   310.993
_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
  Sm  Sm0  1  0.464  0.001  0.259  1.0
  Sm  Sm1  1  0.999  0.536  0.241  1.0
  Sm  Sm2  1  0.468  0.468  0.000  1.0
  Sm  Sm3  1  0.532  0.532  0.500  1.0
  Sm  Sm4  1  0.536  0.999  0.759  1.0
  Sm  Sm5  1  0.001  0.464  0.741  1.0
  Ta  Ta6  1  0.001  0.001  0.500  1.0
  Ta  Ta7  1  0.999  0.999  0.000  1.0
  O  O8  1  0.938  0.062  0.750  1.0
  O  O9  1  0.638  0.362  0.750  1.0
  O  O10  1  0.304  0.051  0.541  1.0
  O  O11  1  0.949  0.696  0.959  1.0
  O  O12  1  0.629  0.371  0.250  1.0
  O  O13  1  0.920  0.677  0.523  1.0
  O  O14  1  0.323  0.080  0.977  1.0
  O  O15  1  0.080  0.323  0.023  1.0
  O  O16  1  0.677  0.920  0.477  1.0
  O  O17  1  0.371  0.629  0.750  1.0
  O  O18  1  0.696  0.949  0.041  1.0
  O  O19  1  0.051  0.304  0.459  1.0
  O  O20  1  0.362  0.638  0.250  1.0
  O  O21  1  0.062  0.938  0.250  1.0
[/CIF]
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The material described by Sm3TaO7 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to one O(1), one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form distorted SmO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra,  a cornercorner with one Sm(1)O7 pentagonal bipyramid, edges with two equivalent Ta(1)O6 octahedra, and edges with three equivalent Sm(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 39-49°. In the second Sm site, Sm(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Ta(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Sm(1)O7 pentagonal bipyramids, and edges with four equivalent Sm(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(1) and two equivalent Ta(1) atoms to form distorted OSm2Ta2 trigonal pyramids that share corners with two equivalent O(4)Sm4 tetrahedra, corners with four equivalent O(5)Sm3Ta tetrahedra, corners with two equivalent O(1)Sm2Ta2 trigonal pyramids,  an edgeedge with one O(2)Sm4 tetrahedra, and edges with two equivalent O(5)Sm3Ta tetrahedra. In the second O site, O(2) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(2)Sm4 tetrahedra, corners with four equivalent O(5)Sm3Ta tetrahedra, corners with four equivalent O(4)Sm4 tetrahedra,  an edgeedge with one O(4)Sm4 tetrahedra, edges with two equivalent O(5)Sm3Ta tetrahedra, and  an edgeedge with one O(1)Sm2Ta2 trigonal pyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sm(2), two equivalent Sm(1), and one Ta(1) atom. In the fourth O site, O(4) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(4)Sm4 tetrahedra, corners with four equivalent O(5)Sm3Ta tetrahedra, corners with four equivalent O(2)Sm4 tetrahedra, corners with two equivalent O(1)Sm2Ta2 trigonal pyramids,  an edgeedge with one O(2)Sm4 tetrahedra, and edges with two equivalent O(5)Sm3Ta tetrahedra. In the fifth O site, O(5) is bonded to one Sm(2), two equivalent Sm(1), and one Ta(1) atom to form distorted OSm3Ta tetrahedra that share corners with two equivalent O(5)Sm3Ta tetrahedra, corners with two equivalent O(2)Sm4 tetrahedra, corners with two equivalent O(4)Sm4 tetrahedra, corners with two equivalent O(1)Sm2Ta2 trigonal pyramids,  an edgeedge with one O(5)Sm3Ta tetrahedra,  an edgeedge with one O(2)Sm4 tetrahedra,  an edgeedge with one O(4)Sm4 tetrahedra, and  an edgeedge with one O(1)Sm2Ta2 trigonal pyramid. is represented by the CIF file [CIF]
data_Sm3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.587
_cell_length_b   6.587
_cell_length_c   7.579
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   108.948
_symmetry_Int_Tables_number   1
_cell_volume   310.993
_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
  Sm  Sm0  1  0.464  0.001  0.259  1.0
  Sm  Sm1  1  0.999  0.536  0.241  1.0
  Sm  Sm2  1  0.468  0.468  0.000  1.0
  Sm  Sm3  1  0.532  0.532  0.500  1.0
  Sm  Sm4  1  0.536  0.999  0.759  1.0
  Sm  Sm5  1  0.001  0.464  0.741  1.0
  Ta  Ta6  1  0.001  0.001  0.500  1.0
  Ta  Ta7  1  0.999  0.999  0.000  1.0
  O  O8  1  0.938  0.062  0.750  1.0
  O  O9  1  0.638  0.362  0.750  1.0
  O  O10  1  0.304  0.051  0.541  1.0
  O  O11  1  0.949  0.696  0.959  1.0
  O  O12  1  0.629  0.371  0.250  1.0
  O  O13  1  0.920  0.677  0.523  1.0
  O  O14  1  0.323  0.080  0.977  1.0
  O  O15  1  0.080  0.323  0.023  1.0
  O  O16  1  0.677  0.920  0.477  1.0
  O  O17  1  0.371  0.629  0.750  1.0
  O  O18  1  0.696  0.949  0.041  1.0
  O  O19  1  0.051  0.304  0.459  1.0
  O  O20  1  0.362  0.638  0.250  1.0
  O  O21  1  0.062  0.938  0.250  1.0
[/CIF]
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