The compound described by Li2SrTa2O7 crystallizes in the orthorhombic Cmcm space group. Li(1) is bonded to one O(3) and four equivalent O(2) atoms to form distorted LiO5 trigonal bipyramids that share corners with two equivalent Sr(1)O12 cuboctahedra, corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Li(1)O5 trigonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with four equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 66°. Sr(1) is bonded to four equivalent O(1), four equivalent O(3), and four equivalent O(4) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, corners with four equivalent Li(1)O5 trigonal bipyramids, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Ta(1)O6 octahedra. Ta(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form TaO6 octahedra that share corners with five equivalent Ta(1)O6 octahedra, corners with two equivalent Li(1)O5 trigonal bipyramids, edges with two equivalent Li(1)O5 trigonal bipyramids, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-20°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1) and two equivalent Ta(1) atoms to form distorted OSr2Ta2 trigonal pyramids that share corners with two equivalent O(2)Li4Ta trigonal bipyramids, corners with two equivalent O(1)Sr2Ta2 trigonal pyramids, and edges with three equivalent O(1)Sr2Ta2 trigonal pyramids. In the second O site, O(2) is bonded to four equivalent Li(1) and one Ta(1) atom to form distorted OLi4Ta trigonal bipyramids that share corners with four equivalent O(2)Li4Ta trigonal bipyramids, corners with two equivalent O(1)Sr2Ta2 trigonal pyramids, and edges with four equivalent O(2)Li4Ta trigonal bipyramids. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Li(1), two equivalent Sr(1), and two equivalent Ta(1) atoms. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to four equivalent Sr(1) and two equivalent Ta(1) atoms. is represented by the CIF file [CIF]
data_SrLi2Ta2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.563
_cell_length_b   5.578
_cell_length_c   9.424
_cell_angle_alpha   107.214
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   279.311
_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
  Sr  Sr0  1  0.750  0.255  0.000  1.0
  Sr  Sr1  1  0.250  0.745  0.000  1.0
  Li  Li2  1  0.500  0.260  0.520  1.0
  Li  Li3  1  0.500  0.740  0.480  1.0
  Li  Li4  1  0.000  0.740  0.480  1.0
  Li  Li5  1  0.000  0.260  0.520  1.0
  Ta  Ta6  1  0.250  0.362  0.232  1.0
  Ta  Ta7  1  0.250  0.130  0.768  1.0
  Ta  Ta8  1  0.750  0.870  0.232  1.0
  Ta  Ta9  1  0.750  0.638  0.768  1.0
  O  O10  1  0.000  0.097  0.193  1.0
  O  O11  1  0.750  0.559  0.562  1.0
  O  O12  1  0.000  0.385  0.769  1.0
  O  O13  1  0.500  0.097  0.193  1.0
  O  O14  1  0.750  0.998  0.438  1.0
  O  O15  1  0.000  0.903  0.807  1.0
  O  O16  1  0.500  0.385  0.769  1.0
  O  O17  1  0.500  0.615  0.231  1.0
  O  O18  1  0.500  0.903  0.807  1.0
  O  O19  1  0.250  0.002  0.562  1.0
  O  O20  1  0.250  0.290  0.000  1.0
  O  O21  1  0.250  0.441  0.438  1.0
  O  O22  1  0.000  0.615  0.231  1.0
  O  O23  1  0.750  0.710  0.000  1.0
[/CIF]
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The compound described by Li2SrTa2O7 crystallizes in the orthorhombic Cmcm space group. Li(1) is bonded to one O(3) and four equivalent O(2) atoms to form distorted LiO5 trigonal bipyramids that share corners with two equivalent Sr(1)O12 cuboctahedra, corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Li(1)O5 trigonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with four equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 66°. Sr(1) is bonded to four equivalent O(1), four equivalent O(3), and four equivalent O(4) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, corners with four equivalent Li(1)O5 trigonal bipyramids, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Ta(1)O6 octahedra. Ta(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form TaO6 octahedra that share corners with five equivalent Ta(1)O6 octahedra, corners with two equivalent Li(1)O5 trigonal bipyramids, edges with two equivalent Li(1)O5 trigonal bipyramids, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-20°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1) and two equivalent Ta(1) atoms to form distorted OSr2Ta2 trigonal pyramids that share corners with two equivalent O(2)Li4Ta trigonal bipyramids, corners with two equivalent O(1)Sr2Ta2 trigonal pyramids, and edges with three equivalent O(1)Sr2Ta2 trigonal pyramids. In the second O site, O(2) is bonded to four equivalent Li(1) and one Ta(1) atom to form distorted OLi4Ta trigonal bipyramids that share corners with four equivalent O(2)Li4Ta trigonal bipyramids, corners with two equivalent O(1)Sr2Ta2 trigonal pyramids, and edges with four equivalent O(2)Li4Ta trigonal bipyramids. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Li(1), two equivalent Sr(1), and two equivalent Ta(1) atoms. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to four equivalent Sr(1) and two equivalent Ta(1) atoms. is represented by the CIF file [CIF]
data_SrLi2Ta2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.563
_cell_length_b   5.578
_cell_length_c   9.424
_cell_angle_alpha   107.214
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   279.311
_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
  Sr  Sr0  1  0.750  0.255  0.000  1.0
  Sr  Sr1  1  0.250  0.745  0.000  1.0
  Li  Li2  1  0.500  0.260  0.520  1.0
  Li  Li3  1  0.500  0.740  0.480  1.0
  Li  Li4  1  0.000  0.740  0.480  1.0
  Li  Li5  1  0.000  0.260  0.520  1.0
  Ta  Ta6  1  0.250  0.362  0.232  1.0
  Ta  Ta7  1  0.250  0.130  0.768  1.0
  Ta  Ta8  1  0.750  0.870  0.232  1.0
  Ta  Ta9  1  0.750  0.638  0.768  1.0
  O  O10  1  0.000  0.097  0.193  1.0
  O  O11  1  0.750  0.559  0.562  1.0
  O  O12  1  0.000  0.385  0.769  1.0
  O  O13  1  0.500  0.097  0.193  1.0
  O  O14  1  0.750  0.998  0.438  1.0
  O  O15  1  0.000  0.903  0.807  1.0
  O  O16  1  0.500  0.385  0.769  1.0
  O  O17  1  0.500  0.615  0.231  1.0
  O  O18  1  0.500  0.903  0.807  1.0
  O  O19  1  0.250  0.002  0.562  1.0
  O  O20  1  0.250  0.290  0.000  1.0
  O  O21  1  0.250  0.441  0.438  1.0
  O  O22  1  0.000  0.615  0.231  1.0
  O  O23  1  0.750  0.710  0.000  1.0
[/CIF]
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