The compound described by Sr2CaV2(Si2O7)2 crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 11-coordinate geometry to one O(7), two equivalent O(1), four equivalent O(4), and four equivalent O(5) atoms. In the second Sr site, Sr(2) is bonded in a 11-coordinate geometry to one O(6), two equivalent O(2), four equivalent O(4), and four equivalent O(5) atoms. Ca(1) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(3), two equivalent O(7), and four equivalent O(4) atoms. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(7) and four equivalent O(4) atoms to form distorted VO5 square pyramids that share corners with four equivalent Si(1)O4 tetrahedra. In the second V site, V(2) is bonded in a 5-coordinate geometry to one O(6) and four equivalent O(5) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent V(1)O5 square pyramids,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), and two equivalent O(5) atoms to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one Ca(1), and two equivalent Si(2) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(2) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ca(1), one Si(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one V(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Sr(2) and one V(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Ca(1), and one V(1) atom. is represented by the CIF card [CIF]
data_Sr2CaV2(Si2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.518
_cell_length_b   7.584
_cell_length_c   7.754
_cell_angle_alpha   90.000
_cell_angle_beta   110.843
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   303.220
_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  0.170  0.750  0.341  1.0
  Sr  Sr1  1  0.807  0.250  0.615  1.0
  Ca  Ca2  1  0.456  0.750  0.913  1.0
  V  V3  1  0.876  0.750  0.752  1.0
  V  V4  1  0.102  0.250  0.205  1.0
  Si  Si5  1  0.383  0.450  0.765  1.0
  Si  Si6  1  0.609  0.511  0.218  1.0
  Si  Si7  1  0.609  0.989  0.218  1.0
  Si  Si8  1  0.383  0.050  0.765  1.0
  O  O9  1  0.615  0.750  0.230  1.0
  O  O10  1  0.341  0.250  0.682  1.0
  O  O11  1  0.497  0.463  0.995  1.0
  O  O12  1  0.497  0.037  0.995  1.0
  O  O13  1  0.587  0.559  0.698  1.0
  O  O14  1  0.903  0.445  0.308  1.0
  O  O15  1  0.404  0.055  0.308  1.0
  O  O16  1  0.112  0.941  0.698  1.0
  O  O17  1  0.978  0.250  0.956  1.0
  O  O18  1  0.000  0.750  0.001  1.0
  O  O19  1  0.903  0.055  0.308  1.0
  O  O20  1  0.587  0.941  0.698  1.0
  O  O21  1  0.112  0.559  0.698  1.0
  O  O22  1  0.404  0.445  0.308  1.0
[/CIF]
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The compound described by Sr2CaV2(Si2O7)2 crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 11-coordinate geometry to one O(7), two equivalent O(1), four equivalent O(4), and four equivalent O(5) atoms. In the second Sr site, Sr(2) is bonded in a 11-coordinate geometry to one O(6), two equivalent O(2), four equivalent O(4), and four equivalent O(5) atoms. Ca(1) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(3), two equivalent O(7), and four equivalent O(4) atoms. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(7) and four equivalent O(4) atoms to form distorted VO5 square pyramids that share corners with four equivalent Si(1)O4 tetrahedra. In the second V site, V(2) is bonded in a 5-coordinate geometry to one O(6) and four equivalent O(5) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent V(1)O5 square pyramids,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), and two equivalent O(5) atoms to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one Ca(1), and two equivalent Si(2) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(2) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ca(1), one Si(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(2), one Ca(1), one V(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Sr(2) and one V(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Ca(1), and one V(1) atom. is represented by the CIF card [CIF]
data_Sr2CaV2(Si2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.518
_cell_length_b   7.584
_cell_length_c   7.754
_cell_angle_alpha   90.000
_cell_angle_beta   110.843
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   303.220
_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  0.170  0.750  0.341  1.0
  Sr  Sr1  1  0.807  0.250  0.615  1.0
  Ca  Ca2  1  0.456  0.750  0.913  1.0
  V  V3  1  0.876  0.750  0.752  1.0
  V  V4  1  0.102  0.250  0.205  1.0
  Si  Si5  1  0.383  0.450  0.765  1.0
  Si  Si6  1  0.609  0.511  0.218  1.0
  Si  Si7  1  0.609  0.989  0.218  1.0
  Si  Si8  1  0.383  0.050  0.765  1.0
  O  O9  1  0.615  0.750  0.230  1.0
  O  O10  1  0.341  0.250  0.682  1.0
  O  O11  1  0.497  0.463  0.995  1.0
  O  O12  1  0.497  0.037  0.995  1.0
  O  O13  1  0.587  0.559  0.698  1.0
  O  O14  1  0.903  0.445  0.308  1.0
  O  O15  1  0.404  0.055  0.308  1.0
  O  O16  1  0.112  0.941  0.698  1.0
  O  O17  1  0.978  0.250  0.956  1.0
  O  O18  1  0.000  0.750  0.001  1.0
  O  O19  1  0.903  0.055  0.308  1.0
  O  O20  1  0.587  0.941  0.698  1.0
  O  O21  1  0.112  0.559  0.698  1.0
  O  O22  1  0.404  0.445  0.308  1.0
[/CIF]
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