The compound described by SrZrSi2O7 crystallizes in the monoclinic P2_1/c space group. Sr(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(6), one O(7), and two equivalent O(1) atoms. Zr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form ZrO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 29-59°. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-53°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Sr(1), one Si(1), and one Si(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(2) atom. In the third O site, O(7) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(2) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Zr(1), and one Si(1) atom. In the fifth O site, O(2) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Zr(1), and one Si(1) atom. In the seventh O site, O(4) is bonded in a distorted linear geometry to one Zr(1) and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrZrSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.205
_cell_length_b   7.858
_cell_length_c   10.194
_cell_angle_alpha   68.215
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   610.285
_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
  Sr  Sr0  1  0.517  0.717  0.293  1.0
  Sr  Sr1  1  0.017  0.283  0.207  1.0
  Sr  Sr2  1  0.483  0.283  0.707  1.0
  Sr  Sr3  1  0.983  0.717  0.793  1.0
  Zr  Zr4  1  0.989  0.744  0.247  1.0
  Zr  Zr5  1  0.489  0.256  0.253  1.0
  Zr  Zr6  1  0.011  0.256  0.753  1.0
  Zr  Zr7  1  0.511  0.744  0.747  1.0
  Si  Si8  1  0.715  0.325  0.959  1.0
  Si  Si9  1  0.215  0.675  0.541  1.0
  Si  Si10  1  0.285  0.675  0.041  1.0
  Si  Si11  1  0.785  0.325  0.459  1.0
  Si  Si12  1  0.749  0.936  0.958  1.0
  Si  Si13  1  0.249  0.064  0.542  1.0
  Si  Si14  1  0.251  0.064  0.042  1.0
  Si  Si15  1  0.751  0.936  0.458  1.0
  O  O16  1  0.905  0.370  0.904  1.0
  O  O17  1  0.405  0.630  0.596  1.0
  O  O18  1  0.095  0.630  0.096  1.0
  O  O19  1  0.595  0.370  0.404  1.0
  O  O20  1  0.705  0.305  0.124  1.0
  O  O21  1  0.205  0.695  0.376  1.0
  O  O22  1  0.295  0.695  0.876  1.0
  O  O23  1  0.795  0.305  0.624  1.0
  O  O24  1  0.593  0.475  0.849  1.0
  O  O25  1  0.093  0.525  0.651  1.0
  O  O26  1  0.407  0.525  0.151  1.0
  O  O27  1  0.907  0.475  0.349  1.0
  O  O28  1  0.634  0.829  0.883  1.0
  O  O29  1  0.134  0.171  0.617  1.0
  O  O30  1  0.366  0.171  0.117  1.0
  O  O31  1  0.866  0.829  0.383  1.0
  O  O32  1  0.843  0.133  0.437  1.0
  O  O33  1  0.343  0.867  0.063  1.0
  O  O34  1  0.157  0.867  0.563  1.0
  O  O35  1  0.657  0.133  0.937  1.0
  O  O36  1  0.729  0.812  0.624  1.0
  O  O37  1  0.229  0.188  0.876  1.0
  O  O38  1  0.271  0.188  0.376  1.0
  O  O39  1  0.771  0.812  0.124  1.0
  O  O40  1  0.579  0.988  0.369  1.0
  O  O41  1  0.079  0.012  0.131  1.0
  O  O42  1  0.421  0.012  0.631  1.0
  O  O43  1  0.921  0.988  0.869  1.0
[/CIF]
.
The compound described by SrZrSi2O7 crystallizes in the monoclinic P2_1/c space group. Sr(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(6), one O(7), and two equivalent O(1) atoms. Zr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form ZrO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 29-59°. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-53°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Sr(1), one Si(1), and one Si(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(2) atom. In the third O site, O(7) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(2) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Zr(1), and one Si(1) atom. In the fifth O site, O(2) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Zr(1), and one Si(1) atom. In the seventh O site, O(4) is bonded in a distorted linear geometry to one Zr(1) and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrZrSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.205
_cell_length_b   7.858
_cell_length_c   10.194
_cell_angle_alpha   68.215
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   610.285
_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
  Sr  Sr0  1  0.517  0.717  0.293  1.0
  Sr  Sr1  1  0.017  0.283  0.207  1.0
  Sr  Sr2  1  0.483  0.283  0.707  1.0
  Sr  Sr3  1  0.983  0.717  0.793  1.0
  Zr  Zr4  1  0.989  0.744  0.247  1.0
  Zr  Zr5  1  0.489  0.256  0.253  1.0
  Zr  Zr6  1  0.011  0.256  0.753  1.0
  Zr  Zr7  1  0.511  0.744  0.747  1.0
  Si  Si8  1  0.715  0.325  0.959  1.0
  Si  Si9  1  0.215  0.675  0.541  1.0
  Si  Si10  1  0.285  0.675  0.041  1.0
  Si  Si11  1  0.785  0.325  0.459  1.0
  Si  Si12  1  0.749  0.936  0.958  1.0
  Si  Si13  1  0.249  0.064  0.542  1.0
  Si  Si14  1  0.251  0.064  0.042  1.0
  Si  Si15  1  0.751  0.936  0.458  1.0
  O  O16  1  0.905  0.370  0.904  1.0
  O  O17  1  0.405  0.630  0.596  1.0
  O  O18  1  0.095  0.630  0.096  1.0
  O  O19  1  0.595  0.370  0.404  1.0
  O  O20  1  0.705  0.305  0.124  1.0
  O  O21  1  0.205  0.695  0.376  1.0
  O  O22  1  0.295  0.695  0.876  1.0
  O  O23  1  0.795  0.305  0.624  1.0
  O  O24  1  0.593  0.475  0.849  1.0
  O  O25  1  0.093  0.525  0.651  1.0
  O  O26  1  0.407  0.525  0.151  1.0
  O  O27  1  0.907  0.475  0.349  1.0
  O  O28  1  0.634  0.829  0.883  1.0
  O  O29  1  0.134  0.171  0.617  1.0
  O  O30  1  0.366  0.171  0.117  1.0
  O  O31  1  0.866  0.829  0.383  1.0
  O  O32  1  0.843  0.133  0.437  1.0
  O  O33  1  0.343  0.867  0.063  1.0
  O  O34  1  0.157  0.867  0.563  1.0
  O  O35  1  0.657  0.133  0.937  1.0
  O  O36  1  0.729  0.812  0.624  1.0
  O  O37  1  0.229  0.188  0.876  1.0
  O  O38  1  0.271  0.188  0.376  1.0
  O  O39  1  0.771  0.812  0.124  1.0
  O  O40  1  0.579  0.988  0.369  1.0
  O  O41  1  0.079  0.012  0.131  1.0
  O  O42  1  0.421  0.012  0.631  1.0
  O  O43  1  0.921  0.988  0.869  1.0
[/CIF]
.