The compound described by Sm3TaO7 crystallizes in the orthorhombic Cmme space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), and four equivalent O(2) atoms. In the second Sm site, Sm(2) is bonded in a distorted hexagonal planar geometry to two equivalent O(3) and four equivalent O(2) atoms. Ta(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. There are three 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 tetrahedra that share corners with two equivalent O(3)Sm4 tetrahedra, corners with four equivalent O(1)Sm2Ta2 tetrahedra, corners with eight equivalent O(2)Sm3Ta tetrahedra, edges with two equivalent O(1)Sm2Ta2 tetrahedra, and edges with four equivalent O(2)Sm3Ta tetrahedra. In the second O site, O(2) is bonded to one Sm(2), two equivalent Sm(1), and one Ta(1) atom to form OSm3Ta tetrahedra that share corners with two equivalent O(3)Sm4 tetrahedra, corners with four equivalent O(1)Sm2Ta2 tetrahedra, corners with eight equivalent O(2)Sm3Ta tetrahedra,  an edgeedge with one O(3)Sm4 tetrahedra, edges with two equivalent O(1)Sm2Ta2 tetrahedra, and edges with two equivalent O(2)Sm3Ta tetrahedra. In the third O site, O(3) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(3)Sm4 tetrahedra, corners with four equivalent O(1)Sm2Ta2 tetrahedra, corners with eight equivalent O(2)Sm3Ta tetrahedra, and edges with four equivalent O(2)Sm3Ta tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.304
_cell_length_b   8.304
_cell_length_c   5.472
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   125.149
_symmetry_Int_Tables_number   1
_cell_volume   308.495
_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  0.382  0.618  0.528  1.0
  Sm  Sm1  1  0.500  0.000  0.000  1.0
  Sm  Sm2  1  0.882  0.118  0.472  1.0
  Sm  Sm3  1  0.618  0.382  0.472  1.0
  Sm  Sm4  1  0.000  0.500  0.000  1.0
  Sm  Sm5  1  0.118  0.882  0.528  1.0
  Ta  Ta6  1  0.750  0.750  0.000  1.0
  Ta  Ta7  1  0.250  0.250  0.000  1.0
  O  O8  1  0.990  0.010  0.208  1.0
  O  O9  1  0.510  0.490  0.208  1.0
  O  O10  1  0.490  0.510  0.792  1.0
  O  O11  1  0.661  0.893  0.767  1.0
  O  O12  1  0.750  0.250  0.243  1.0
  O  O13  1  0.010  0.990  0.792  1.0
  O  O14  1  0.107  0.339  0.767  1.0
  O  O15  1  0.839  0.607  0.767  1.0
  O  O16  1  0.161  0.393  0.233  1.0
  O  O17  1  0.250  0.750  0.757  1.0
  O  O18  1  0.393  0.161  0.767  1.0
  O  O19  1  0.607  0.839  0.233  1.0
  O  O20  1  0.339  0.107  0.233  1.0
  O  O21  1  0.893  0.661  0.233  1.0
[/CIF]
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The compound described by Sm3TaO7 crystallizes in the orthorhombic Cmme space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), and four equivalent O(2) atoms. In the second Sm site, Sm(2) is bonded in a distorted hexagonal planar geometry to two equivalent O(3) and four equivalent O(2) atoms. Ta(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. There are three 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 tetrahedra that share corners with two equivalent O(3)Sm4 tetrahedra, corners with four equivalent O(1)Sm2Ta2 tetrahedra, corners with eight equivalent O(2)Sm3Ta tetrahedra, edges with two equivalent O(1)Sm2Ta2 tetrahedra, and edges with four equivalent O(2)Sm3Ta tetrahedra. In the second O site, O(2) is bonded to one Sm(2), two equivalent Sm(1), and one Ta(1) atom to form OSm3Ta tetrahedra that share corners with two equivalent O(3)Sm4 tetrahedra, corners with four equivalent O(1)Sm2Ta2 tetrahedra, corners with eight equivalent O(2)Sm3Ta tetrahedra,  an edgeedge with one O(3)Sm4 tetrahedra, edges with two equivalent O(1)Sm2Ta2 tetrahedra, and edges with two equivalent O(2)Sm3Ta tetrahedra. In the third O site, O(3) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(3)Sm4 tetrahedra, corners with four equivalent O(1)Sm2Ta2 tetrahedra, corners with eight equivalent O(2)Sm3Ta tetrahedra, and edges with four equivalent O(2)Sm3Ta tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.304
_cell_length_b   8.304
_cell_length_c   5.472
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   125.149
_symmetry_Int_Tables_number   1
_cell_volume   308.495
_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  0.382  0.618  0.528  1.0
  Sm  Sm1  1  0.500  0.000  0.000  1.0
  Sm  Sm2  1  0.882  0.118  0.472  1.0
  Sm  Sm3  1  0.618  0.382  0.472  1.0
  Sm  Sm4  1  0.000  0.500  0.000  1.0
  Sm  Sm5  1  0.118  0.882  0.528  1.0
  Ta  Ta6  1  0.750  0.750  0.000  1.0
  Ta  Ta7  1  0.250  0.250  0.000  1.0
  O  O8  1  0.990  0.010  0.208  1.0
  O  O9  1  0.510  0.490  0.208  1.0
  O  O10  1  0.490  0.510  0.792  1.0
  O  O11  1  0.661  0.893  0.767  1.0
  O  O12  1  0.750  0.250  0.243  1.0
  O  O13  1  0.010  0.990  0.792  1.0
  O  O14  1  0.107  0.339  0.767  1.0
  O  O15  1  0.839  0.607  0.767  1.0
  O  O16  1  0.161  0.393  0.233  1.0
  O  O17  1  0.250  0.750  0.757  1.0
  O  O18  1  0.393  0.161  0.767  1.0
  O  O19  1  0.607  0.839  0.233  1.0
  O  O20  1  0.339  0.107  0.233  1.0
  O  O21  1  0.893  0.661  0.233  1.0
[/CIF]
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