The compound described by CaV(SiO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. V(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form VO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent V(1)O6 octahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-57°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1), one V(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Ca(1), two equivalent V(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OCaV2Si trigonal pyramids. is represented by the CIF file [CIF]
data_CaV(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.310
_cell_length_b   6.799
_cell_length_c   6.799
_cell_angle_alpha   84.680
_cell_angle_beta   78.869
_cell_angle_gamma   78.868
_symmetry_Int_Tables_number   1
_cell_volume   235.927
_cell_formula_units_Z   2
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
  Ca  Ca0  1  0.750  0.298  0.702  1.0
  Ca  Ca1  1  0.250  0.702  0.298  1.0
  V  V2  1  0.750  0.910  0.090  1.0
  V  V3  1  0.250  0.090  0.910  1.0
  Si  Si4  1  0.264  0.197  0.382  1.0
  Si  Si5  1  0.236  0.618  0.803  1.0
  Si  Si6  1  0.764  0.382  0.197  1.0
  Si  Si7  1  0.736  0.803  0.618  1.0
  O  O8  1  0.503  0.331  0.368  1.0
  O  O9  1  0.997  0.632  0.669  1.0
  O  O10  1  0.497  0.669  0.632  1.0
  O  O11  1  0.003  0.368  0.331  1.0
  O  O12  1  0.174  0.120  0.610  1.0
  O  O13  1  0.326  0.390  0.880  1.0
  O  O14  1  0.826  0.880  0.390  1.0
  O  O15  1  0.674  0.610  0.120  1.0
  O  O16  1  0.847  0.214  0.030  1.0
  O  O17  1  0.653  0.970  0.786  1.0
  O  O18  1  0.347  0.030  0.214  1.0
  O  O19  1  0.153  0.786  0.970  1.0
[/CIF]
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The compound described by CaV(SiO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. V(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form VO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent V(1)O6 octahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-57°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1), one V(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Ca(1), two equivalent V(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OCaV2Si trigonal pyramids. is represented by the CIF file [CIF]
data_CaV(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.310
_cell_length_b   6.799
_cell_length_c   6.799
_cell_angle_alpha   84.680
_cell_angle_beta   78.869
_cell_angle_gamma   78.868
_symmetry_Int_Tables_number   1
_cell_volume   235.927
_cell_formula_units_Z   2
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
  Ca  Ca0  1  0.750  0.298  0.702  1.0
  Ca  Ca1  1  0.250  0.702  0.298  1.0
  V  V2  1  0.750  0.910  0.090  1.0
  V  V3  1  0.250  0.090  0.910  1.0
  Si  Si4  1  0.264  0.197  0.382  1.0
  Si  Si5  1  0.236  0.618  0.803  1.0
  Si  Si6  1  0.764  0.382  0.197  1.0
  Si  Si7  1  0.736  0.803  0.618  1.0
  O  O8  1  0.503  0.331  0.368  1.0
  O  O9  1  0.997  0.632  0.669  1.0
  O  O10  1  0.497  0.669  0.632  1.0
  O  O11  1  0.003  0.368  0.331  1.0
  O  O12  1  0.174  0.120  0.610  1.0
  O  O13  1  0.326  0.390  0.880  1.0
  O  O14  1  0.826  0.880  0.390  1.0
  O  O15  1  0.674  0.610  0.120  1.0
  O  O16  1  0.847  0.214  0.030  1.0
  O  O17  1  0.653  0.970  0.786  1.0
  O  O18  1  0.347  0.030  0.214  1.0
  O  O19  1  0.153  0.786  0.970  1.0
[/CIF]
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