The structure described by Sm2Zr2O7 crystallizes in the monoclinic P2_1/c 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), one O(4), one O(5), two equivalent O(2), and two equivalent O(6) atoms. In the second Sm site, Sm(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(7) atom to form a mixture of distorted edge and corner-sharing ZrO5 trigonal bipyramids. In the second Zr site, Zr(2) is bonded to one O(4), one O(5), one O(6), one O(7), and two equivalent O(1) atoms to form distorted ZrO6 pentagonal pyramids that share corners with two equivalent Zr(1)O5 trigonal bipyramids,  an edgeedge with one Zr(2)O6 pentagonal pyramid, and  an edgeedge with one Zr(1)O5 trigonal bipyramid. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Sm(2), one Zr(1), and two equivalent Zr(2) atoms to form distorted OSmZr3 trigonal pyramids that share corners with two equivalent O(2)Sm3Zr tetrahedra,  a cornercorner with one O(6)Sm3Zr trigonal pyramid,  an edgeedge with one O(6)Sm3Zr trigonal pyramid, and  an edgeedge with one O(1)SmZr3 trigonal pyramid. In the second O site, O(2) is bonded to one Sm(2), two equivalent Sm(1), and one Zr(1) atom to form distorted OSm3Zr tetrahedra that share corners with two equivalent O(2)Sm3Zr tetrahedra, corners with two equivalent O(1)SmZr3 trigonal pyramids, corners with three equivalent O(6)Sm3Zr trigonal pyramids, and  an edgeedge with one O(6)Sm3Zr trigonal pyramid. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Sm(1), one Sm(2), and one Zr(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Sm(1), one Zr(1), and one Zr(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Sm(1), one Sm(2), and one Zr(2) atom. In the sixth O site, O(6) is bonded to one Sm(2), two equivalent Sm(1), and one Zr(2) atom to form distorted OSm3Zr trigonal pyramids that share corners with three equivalent O(2)Sm3Zr tetrahedra,  a cornercorner with one O(1)SmZr3 trigonal pyramid,  an edgeedge with one O(2)Sm3Zr tetrahedra,  an edgeedge with one O(6)Sm3Zr trigonal pyramid, and  an edgeedge with one O(1)SmZr3 trigonal pyramid. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Sm(2), one Zr(1), and one Zr(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2Zr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.086
_cell_length_b   7.524
_cell_length_c   12.262
_cell_angle_alpha   81.066
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   645.831
_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
  Sm  Sm0  1  0.886  0.523  0.638  1.0
  Sm  Sm1  1  0.386  0.477  0.862  1.0
  Sm  Sm2  1  0.674  0.750  0.385  1.0
  Sm  Sm3  1  0.174  0.250  0.115  1.0
  Sm  Sm4  1  0.826  0.750  0.885  1.0
  Sm  Sm5  1  0.326  0.250  0.615  1.0
  Sm  Sm6  1  0.614  0.523  0.138  1.0
  Sm  Sm7  1  0.114  0.477  0.362  1.0
  Zr  Zr8  1  0.858  0.252  0.898  1.0
  Zr  Zr9  1  0.358  0.748  0.602  1.0
  Zr  Zr10  1  0.108  0.944  0.388  1.0
  Zr  Zr11  1  0.608  0.056  0.112  1.0
  Zr  Zr12  1  0.392  0.944  0.888  1.0
  Zr  Zr13  1  0.892  0.056  0.612  1.0
  Zr  Zr14  1  0.642  0.252  0.398  1.0
  Zr  Zr15  1  0.142  0.748  0.102  1.0
  O  O16  1  0.681  0.010  0.937  1.0
  O  O17  1  0.229  0.522  0.675  1.0
  O  O18  1  0.100  0.375  0.931  1.0
  O  O19  1  0.063  0.818  0.250  1.0
  O  O20  1  0.607  0.805  0.200  1.0
  O  O21  1  0.600  0.625  0.569  1.0
  O  O22  1  0.987  0.688  0.469  1.0
  O  O23  1  0.729  0.478  0.825  1.0
  O  O24  1  0.368  0.823  0.424  1.0
  O  O25  1  0.437  0.818  0.750  1.0
  O  O26  1  0.181  0.990  0.563  1.0
  O  O27  1  0.893  0.805  0.700  1.0
  O  O28  1  0.868  0.177  0.076  1.0
  O  O29  1  0.513  0.688  0.969  1.0
  O  O30  1  0.487  0.312  0.031  1.0
  O  O31  1  0.132  0.823  0.924  1.0
  O  O32  1  0.107  0.195  0.300  1.0
  O  O33  1  0.819  0.010  0.437  1.0
  O  O34  1  0.563  0.182  0.250  1.0
  O  O35  1  0.632  0.177  0.576  1.0
  O  O36  1  0.271  0.522  0.175  1.0
  O  O37  1  0.013  0.312  0.531  1.0
  O  O38  1  0.400  0.375  0.431  1.0
  O  O39  1  0.393  0.195  0.800  1.0
  O  O40  1  0.937  0.182  0.750  1.0
  O  O41  1  0.900  0.625  0.069  1.0
  O  O42  1  0.771  0.478  0.325  1.0
  O  O43  1  0.319  0.990  0.063  1.0
[/CIF]
.
The structure described by Sm2Zr2O7 crystallizes in the monoclinic P2_1/c 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), one O(4), one O(5), two equivalent O(2), and two equivalent O(6) atoms. In the second Sm site, Sm(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(7) atom to form a mixture of distorted edge and corner-sharing ZrO5 trigonal bipyramids. In the second Zr site, Zr(2) is bonded to one O(4), one O(5), one O(6), one O(7), and two equivalent O(1) atoms to form distorted ZrO6 pentagonal pyramids that share corners with two equivalent Zr(1)O5 trigonal bipyramids,  an edgeedge with one Zr(2)O6 pentagonal pyramid, and  an edgeedge with one Zr(1)O5 trigonal bipyramid. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Sm(2), one Zr(1), and two equivalent Zr(2) atoms to form distorted OSmZr3 trigonal pyramids that share corners with two equivalent O(2)Sm3Zr tetrahedra,  a cornercorner with one O(6)Sm3Zr trigonal pyramid,  an edgeedge with one O(6)Sm3Zr trigonal pyramid, and  an edgeedge with one O(1)SmZr3 trigonal pyramid. In the second O site, O(2) is bonded to one Sm(2), two equivalent Sm(1), and one Zr(1) atom to form distorted OSm3Zr tetrahedra that share corners with two equivalent O(2)Sm3Zr tetrahedra, corners with two equivalent O(1)SmZr3 trigonal pyramids, corners with three equivalent O(6)Sm3Zr trigonal pyramids, and  an edgeedge with one O(6)Sm3Zr trigonal pyramid. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Sm(1), one Sm(2), and one Zr(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Sm(1), one Zr(1), and one Zr(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Sm(1), one Sm(2), and one Zr(2) atom. In the sixth O site, O(6) is bonded to one Sm(2), two equivalent Sm(1), and one Zr(2) atom to form distorted OSm3Zr trigonal pyramids that share corners with three equivalent O(2)Sm3Zr tetrahedra,  a cornercorner with one O(1)SmZr3 trigonal pyramid,  an edgeedge with one O(2)Sm3Zr tetrahedra,  an edgeedge with one O(6)Sm3Zr trigonal pyramid, and  an edgeedge with one O(1)SmZr3 trigonal pyramid. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Sm(2), one Zr(1), and one Zr(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2Zr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.086
_cell_length_b   7.524
_cell_length_c   12.262
_cell_angle_alpha   81.066
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   645.831
_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
  Sm  Sm0  1  0.886  0.523  0.638  1.0
  Sm  Sm1  1  0.386  0.477  0.862  1.0
  Sm  Sm2  1  0.674  0.750  0.385  1.0
  Sm  Sm3  1  0.174  0.250  0.115  1.0
  Sm  Sm4  1  0.826  0.750  0.885  1.0
  Sm  Sm5  1  0.326  0.250  0.615  1.0
  Sm  Sm6  1  0.614  0.523  0.138  1.0
  Sm  Sm7  1  0.114  0.477  0.362  1.0
  Zr  Zr8  1  0.858  0.252  0.898  1.0
  Zr  Zr9  1  0.358  0.748  0.602  1.0
  Zr  Zr10  1  0.108  0.944  0.388  1.0
  Zr  Zr11  1  0.608  0.056  0.112  1.0
  Zr  Zr12  1  0.392  0.944  0.888  1.0
  Zr  Zr13  1  0.892  0.056  0.612  1.0
  Zr  Zr14  1  0.642  0.252  0.398  1.0
  Zr  Zr15  1  0.142  0.748  0.102  1.0
  O  O16  1  0.681  0.010  0.937  1.0
  O  O17  1  0.229  0.522  0.675  1.0
  O  O18  1  0.100  0.375  0.931  1.0
  O  O19  1  0.063  0.818  0.250  1.0
  O  O20  1  0.607  0.805  0.200  1.0
  O  O21  1  0.600  0.625  0.569  1.0
  O  O22  1  0.987  0.688  0.469  1.0
  O  O23  1  0.729  0.478  0.825  1.0
  O  O24  1  0.368  0.823  0.424  1.0
  O  O25  1  0.437  0.818  0.750  1.0
  O  O26  1  0.181  0.990  0.563  1.0
  O  O27  1  0.893  0.805  0.700  1.0
  O  O28  1  0.868  0.177  0.076  1.0
  O  O29  1  0.513  0.688  0.969  1.0
  O  O30  1  0.487  0.312  0.031  1.0
  O  O31  1  0.132  0.823  0.924  1.0
  O  O32  1  0.107  0.195  0.300  1.0
  O  O33  1  0.819  0.010  0.437  1.0
  O  O34  1  0.563  0.182  0.250  1.0
  O  O35  1  0.632  0.177  0.576  1.0
  O  O36  1  0.271  0.522  0.175  1.0
  O  O37  1  0.013  0.312  0.531  1.0
  O  O38  1  0.400  0.375  0.431  1.0
  O  O39  1  0.393  0.195  0.800  1.0
  O  O40  1  0.937  0.182  0.750  1.0
  O  O41  1  0.900  0.625  0.069  1.0
  O  O42  1  0.771  0.478  0.325  1.0
  O  O43  1  0.319  0.990  0.063  1.0
[/CIF]
.