The structure described by Sr2CaV2(Si2O7)2 crystallizes in the triclinic P1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(12), one O(14), one O(5), one O(7), and one O(8) atom. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(11), one O(12), one O(14), one O(2), one O(5), one O(7), one O(8), and one O(9) atom. Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(13), one O(3), one O(5), one O(6), and one O(9) atom. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(10), one O(12), one O(13), one O(8), and one O(9) atom to form VO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and  an edgeedge with one V(2)O6 octahedra. In the second V site, V(2) is bonded to one O(10), one O(11), one O(4), one O(6), one O(7), and one O(9) atom to form distorted VO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  an edgeedge with one Si(3)O4 tetrahedra, and  an edgeedge with one V(1)O5 trigonal bipyramid. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one V(1)O5 trigonal bipyramid. In the second Si site, Si(2) is bonded to one O(1), one O(14), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the third Si site, Si(3) is bonded to one O(1), one O(11), one O(4), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one V(2)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the fourth Si site, Si(4) is bonded to one O(12), one O(2), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent V(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 63°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1), one Si(2), and one Si(3) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Sr(2), one Si(1), and one Si(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Si(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one V(2), one Si(3), and one Si(4) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to one Sr(1), one Sr(2), one Ca(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(1), one V(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(1), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Sr(2), one Ca(1), one V(1), and one V(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Sr(1), one Ca(1), one V(1), and one V(2) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(2), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(1), and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Ca(1), one V(1), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Sr(1), one Sr(2), and one Si(2) atom. is represented by the CIF file [CIF]
data_Sr2CaV2(Si2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.869
_cell_length_b   7.342
_cell_length_c   8.223
_cell_angle_alpha   95.235
_cell_angle_beta   113.213
_cell_angle_gamma   75.492
_symmetry_Int_Tables_number   1
_cell_volume   315.235
_cell_formula_units_Z   1
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  0.316  0.784  0.476  1.0
  Sr  Sr1  1  0.746  0.253  0.585  1.0
  Ca  Ca2  1  0.958  0.515  0.997  1.0
  V  V3  1  0.987  0.894  0.842  1.0
  V  V4  1  0.977  0.100  0.146  1.0
  Si  Si5  1  0.325  0.494  0.806  1.0
  Si  Si6  1  0.626  0.518  0.212  1.0
  Si  Si7  1  0.603  0.962  0.215  1.0
  Si  Si8  1  0.418  0.066  0.804  1.0
  O  O9  1  0.657  0.732  0.183  1.0
  O  O10  1  0.284  0.282  0.726  1.0
  O  O11  1  0.401  0.472  0.023  1.0
  O  O12  1  0.556  0.060  0.022  1.0
  O  O13  1  0.540  0.545  0.755  1.0
  O  O14  1  0.897  0.380  0.222  1.0
  O  O15  1  0.381  0.042  0.291  1.0
  O  O16  1  0.194  0.952  0.726  1.0
  O  O17  1  0.956  0.182  0.924  1.0
  O  O18  1  0.044  0.829  0.072  1.0
  O  O19  1  0.871  0.018  0.344  1.0
  O  O20  1  0.616  0.972  0.707  1.0
  O  O21  1  0.036  0.626  0.743  1.0
  O  O22  1  0.535  0.506  0.369  1.0
[/CIF]
.
The structure described by Sr2CaV2(Si2O7)2 crystallizes in the triclinic P1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(12), one O(14), one O(5), one O(7), and one O(8) atom. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(11), one O(12), one O(14), one O(2), one O(5), one O(7), one O(8), and one O(9) atom. Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(13), one O(3), one O(5), one O(6), and one O(9) atom. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(10), one O(12), one O(13), one O(8), and one O(9) atom to form VO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and  an edgeedge with one V(2)O6 octahedra. In the second V site, V(2) is bonded to one O(10), one O(11), one O(4), one O(6), one O(7), and one O(9) atom to form distorted VO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  an edgeedge with one Si(3)O4 tetrahedra, and  an edgeedge with one V(1)O5 trigonal bipyramid. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one V(1)O5 trigonal bipyramid. In the second Si site, Si(2) is bonded to one O(1), one O(14), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the third Si site, Si(3) is bonded to one O(1), one O(11), one O(4), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  an edgeedge with one V(2)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the fourth Si site, Si(4) is bonded to one O(12), one O(2), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent V(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 63°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1), one Si(2), and one Si(3) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Sr(2), one Si(1), and one Si(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Si(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one V(2), one Si(3), and one Si(4) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to one Sr(1), one Sr(2), one Ca(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(1), one V(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(1), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Sr(2), one Ca(1), one V(1), and one V(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Sr(1), one Ca(1), one V(1), and one V(2) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(2), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(1), and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Ca(1), one V(1), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Sr(1), one Sr(2), and one Si(2) atom. is represented by the CIF file [CIF]
data_Sr2CaV2(Si2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.869
_cell_length_b   7.342
_cell_length_c   8.223
_cell_angle_alpha   95.235
_cell_angle_beta   113.213
_cell_angle_gamma   75.492
_symmetry_Int_Tables_number   1
_cell_volume   315.235
_cell_formula_units_Z   1
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  0.316  0.784  0.476  1.0
  Sr  Sr1  1  0.746  0.253  0.585  1.0
  Ca  Ca2  1  0.958  0.515  0.997  1.0
  V  V3  1  0.987  0.894  0.842  1.0
  V  V4  1  0.977  0.100  0.146  1.0
  Si  Si5  1  0.325  0.494  0.806  1.0
  Si  Si6  1  0.626  0.518  0.212  1.0
  Si  Si7  1  0.603  0.962  0.215  1.0
  Si  Si8  1  0.418  0.066  0.804  1.0
  O  O9  1  0.657  0.732  0.183  1.0
  O  O10  1  0.284  0.282  0.726  1.0
  O  O11  1  0.401  0.472  0.023  1.0
  O  O12  1  0.556  0.060  0.022  1.0
  O  O13  1  0.540  0.545  0.755  1.0
  O  O14  1  0.897  0.380  0.222  1.0
  O  O15  1  0.381  0.042  0.291  1.0
  O  O16  1  0.194  0.952  0.726  1.0
  O  O17  1  0.956  0.182  0.924  1.0
  O  O18  1  0.044  0.829  0.072  1.0
  O  O19  1  0.871  0.018  0.344  1.0
  O  O20  1  0.616  0.972  0.707  1.0
  O  O21  1  0.036  0.626  0.743  1.0
  O  O22  1  0.535  0.506  0.369  1.0
[/CIF]
.