The material described by Li2BaP2O7 crystallizes in the monoclinic C2/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(4) and two equivalent O(7) atoms to form LiO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent Li(3)O5 trigonal bipyramids. In the second Li site, Li(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(6) atoms. In the third Li site, Li(3) is bonded to one O(1), one O(4), one O(6), and two equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra,  an edgeedge with one P(2)O4 tetrahedra, and  an edgeedge with one Li(3)O5 trigonal bipyramid. Ba(1) is bonded in a 9-coordinate geometry to one O(3), one O(4), one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Li(3)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one Li(3)O5 trigonal bipyramid, and  an edgeedge with one Li(3)O5 trigonal bipyramid. There are seven inequivalent O sites. In the first O site, O(7) is bonded in a 2-coordinate geometry to one Li(1), one Ba(1), and one P(1) atom. In the second O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Li(3), two equivalent Ba(1), and one P(1) atom. In the third O site, O(2) is bonded in a 2-coordinate geometry to one Li(2), two equivalent Ba(1), and one P(2) atom. In the fourth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Li(3), one Ba(1), and one P(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Li(3), one Ba(1), and one P(2) atom. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Li(3), one Ba(1), and one P(2) atom. In the seventh O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one P(1), and one P(2) atom. is represented by the CIF card [CIF]
data_BaLi2P2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.154
_cell_length_b   7.154
_cell_length_c   13.996
_cell_angle_alpha   89.665
_cell_angle_beta   89.665
_cell_angle_gamma   119.349
_symmetry_Int_Tables_number   1
_cell_volume   624.345
_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
  Ba  Ba0  1  0.161  0.212  0.379  1.0
  Ba  Ba1  1  0.788  0.839  0.121  1.0
  Ba  Ba2  1  0.839  0.788  0.621  1.0
  Ba  Ba3  1  0.212  0.161  0.879  1.0
  Li  Li4  1  0.234  0.766  0.250  1.0
  Li  Li5  1  0.766  0.234  0.750  1.0
  Li  Li6  1  0.767  0.233  0.250  1.0
  Li  Li7  1  0.233  0.767  0.750  1.0
  Li  Li8  1  0.269  0.801  0.491  1.0
  Li  Li9  1  0.199  0.731  0.009  1.0
  Li  Li10  1  0.731  0.199  0.509  1.0
  Li  Li11  1  0.801  0.269  0.991  1.0
  P  P12  1  0.850  0.591  0.365  1.0
  P  P13  1  0.409  0.150  0.135  1.0
  P  P14  1  0.150  0.409  0.635  1.0
  P  P15  1  0.591  0.850  0.865  1.0
  P  P16  1  0.576  0.786  0.381  1.0
  P  P17  1  0.214  0.424  0.119  1.0
  P  P18  1  0.424  0.214  0.619  1.0
  P  P19  1  0.786  0.576  0.881  1.0
  O  O20  1  0.991  0.763  0.437  1.0
  O  O21  1  0.237  0.009  0.063  1.0
  O  O22  1  0.009  0.237  0.563  1.0
  O  O23  1  0.763  0.991  0.937  1.0
  O  O24  1  0.939  0.717  0.801  1.0
  O  O25  1  0.283  0.061  0.699  1.0
  O  O26  1  0.061  0.283  0.199  1.0
  O  O27  1  0.717  0.939  0.301  1.0
  O  O28  1  0.887  0.636  0.980  1.0
  O  O29  1  0.364  0.113  0.520  1.0
  O  O30  1  0.113  0.364  0.020  1.0
  O  O31  1  0.636  0.887  0.480  1.0
  O  O32  1  0.681  0.333  0.865  1.0
  O  O33  1  0.667  0.319  0.635  1.0
  O  O34  1  0.319  0.667  0.135  1.0
  O  O35  1  0.333  0.681  0.365  1.0
  O  O36  1  0.574  0.611  0.878  1.0
  O  O37  1  0.389  0.426  0.622  1.0
  O  O38  1  0.426  0.389  0.122  1.0
  O  O39  1  0.611  0.574  0.378  1.0
  O  O40  1  0.364  0.810  0.887  1.0
  O  O41  1  0.190  0.636  0.613  1.0
  O  O42  1  0.636  0.190  0.113  1.0
  O  O43  1  0.810  0.364  0.387  1.0
  O  O44  1  0.653  0.919  0.761  1.0
  O  O45  1  0.081  0.347  0.739  1.0
  O  O46  1  0.347  0.081  0.239  1.0
  O  O47  1  0.919  0.653  0.261  1.0
[/CIF]
.
The material described by Li2BaP2O7 crystallizes in the monoclinic C2/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(4) and two equivalent O(7) atoms to form LiO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent Li(3)O5 trigonal bipyramids. In the second Li site, Li(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(6) atoms. In the third Li site, Li(3) is bonded to one O(1), one O(4), one O(6), and two equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra,  an edgeedge with one P(2)O4 tetrahedra, and  an edgeedge with one Li(3)O5 trigonal bipyramid. Ba(1) is bonded in a 9-coordinate geometry to one O(3), one O(4), one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent Li(3)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one Li(3)O5 trigonal bipyramid, and  an edgeedge with one Li(3)O5 trigonal bipyramid. There are seven inequivalent O sites. In the first O site, O(7) is bonded in a 2-coordinate geometry to one Li(1), one Ba(1), and one P(1) atom. In the second O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Li(3), two equivalent Ba(1), and one P(1) atom. In the third O site, O(2) is bonded in a 2-coordinate geometry to one Li(2), two equivalent Ba(1), and one P(2) atom. In the fourth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Li(3), one Ba(1), and one P(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Li(3), one Ba(1), and one P(2) atom. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Li(3), one Ba(1), and one P(2) atom. In the seventh O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one P(1), and one P(2) atom. is represented by the CIF card [CIF]
data_BaLi2P2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.154
_cell_length_b   7.154
_cell_length_c   13.996
_cell_angle_alpha   89.665
_cell_angle_beta   89.665
_cell_angle_gamma   119.349
_symmetry_Int_Tables_number   1
_cell_volume   624.345
_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
  Ba  Ba0  1  0.161  0.212  0.379  1.0
  Ba  Ba1  1  0.788  0.839  0.121  1.0
  Ba  Ba2  1  0.839  0.788  0.621  1.0
  Ba  Ba3  1  0.212  0.161  0.879  1.0
  Li  Li4  1  0.234  0.766  0.250  1.0
  Li  Li5  1  0.766  0.234  0.750  1.0
  Li  Li6  1  0.767  0.233  0.250  1.0
  Li  Li7  1  0.233  0.767  0.750  1.0
  Li  Li8  1  0.269  0.801  0.491  1.0
  Li  Li9  1  0.199  0.731  0.009  1.0
  Li  Li10  1  0.731  0.199  0.509  1.0
  Li  Li11  1  0.801  0.269  0.991  1.0
  P  P12  1  0.850  0.591  0.365  1.0
  P  P13  1  0.409  0.150  0.135  1.0
  P  P14  1  0.150  0.409  0.635  1.0
  P  P15  1  0.591  0.850  0.865  1.0
  P  P16  1  0.576  0.786  0.381  1.0
  P  P17  1  0.214  0.424  0.119  1.0
  P  P18  1  0.424  0.214  0.619  1.0
  P  P19  1  0.786  0.576  0.881  1.0
  O  O20  1  0.991  0.763  0.437  1.0
  O  O21  1  0.237  0.009  0.063  1.0
  O  O22  1  0.009  0.237  0.563  1.0
  O  O23  1  0.763  0.991  0.937  1.0
  O  O24  1  0.939  0.717  0.801  1.0
  O  O25  1  0.283  0.061  0.699  1.0
  O  O26  1  0.061  0.283  0.199  1.0
  O  O27  1  0.717  0.939  0.301  1.0
  O  O28  1  0.887  0.636  0.980  1.0
  O  O29  1  0.364  0.113  0.520  1.0
  O  O30  1  0.113  0.364  0.020  1.0
  O  O31  1  0.636  0.887  0.480  1.0
  O  O32  1  0.681  0.333  0.865  1.0
  O  O33  1  0.667  0.319  0.635  1.0
  O  O34  1  0.319  0.667  0.135  1.0
  O  O35  1  0.333  0.681  0.365  1.0
  O  O36  1  0.574  0.611  0.878  1.0
  O  O37  1  0.389  0.426  0.622  1.0
  O  O38  1  0.426  0.389  0.122  1.0
  O  O39  1  0.611  0.574  0.378  1.0
  O  O40  1  0.364  0.810  0.887  1.0
  O  O41  1  0.190  0.636  0.613  1.0
  O  O42  1  0.636  0.190  0.113  1.0
  O  O43  1  0.810  0.364  0.387  1.0
  O  O44  1  0.653  0.919  0.761  1.0
  O  O45  1  0.081  0.347  0.739  1.0
  O  O46  1  0.347  0.081  0.239  1.0
  O  O47  1  0.919  0.653  0.261  1.0
[/CIF]
.