The material described by MgTiTa(PO4)3 crystallizes in the trigonal R3c space group. Mg(1) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form distorted MgO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra,  a faceface with one Ti(1)O6 octahedra, and  a faceface with one Ta(1)O6 octahedra. Ti(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form distorted TiO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and  a faceface with one Mg(1)O6 octahedra. Ta(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form TaO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and  a faceface with one Mg(1)O6 octahedra. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Ti(1)O6 octahedra, and corners with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-49°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ta(1) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Ti(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Ta(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgTaTi(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.595
_cell_length_b   8.595
_cell_length_c   8.595
_cell_angle_alpha   61.569
_cell_angle_beta   61.569
_cell_angle_gamma   61.569
_symmetry_Int_Tables_number   1
_cell_volume   464.796
_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
  Mg  Mg0  1  0.004  0.004  0.004  1.0
  Mg  Mg1  1  0.504  0.504  0.504  1.0
  Ta  Ta2  1  0.356  0.356  0.356  1.0
  Ta  Ta3  1  0.856  0.856  0.856  1.0
  Ti  Ti4  1  0.145  0.145  0.145  1.0
  Ti  Ti5  1  0.645  0.645  0.645  1.0
  P  P6  1  0.045  0.450  0.752  1.0
  P  P7  1  0.450  0.752  0.045  1.0
  P  P8  1  0.752  0.045  0.450  1.0
  P  P9  1  0.252  0.950  0.545  1.0
  P  P10  1  0.545  0.252  0.950  1.0
  P  P11  1  0.950  0.545  0.252  1.0
  O  O12  1  0.109  0.508  0.316  1.0
  O  O13  1  0.316  0.109  0.508  1.0
  O  O14  1  0.060  0.258  0.908  1.0
  O  O15  1  0.508  0.316  0.109  1.0
  O  O16  1  0.008  0.609  0.816  1.0
  O  O17  1  0.241  0.440  0.593  1.0
  O  O18  1  0.258  0.908  0.060  1.0
  O  O19  1  0.440  0.593  0.241  1.0
  O  O20  1  0.181  0.994  0.391  1.0
  O  O21  1  0.593  0.241  0.440  1.0
  O  O22  1  0.093  0.940  0.741  1.0
  O  O23  1  0.391  0.181  0.994  1.0
  O  O24  1  0.609  0.816  0.008  1.0
  O  O25  1  0.908  0.060  0.258  1.0
  O  O26  1  0.408  0.758  0.560  1.0
  O  O27  1  0.816  0.008  0.609  1.0
  O  O28  1  0.560  0.408  0.758  1.0
  O  O29  1  0.741  0.093  0.940  1.0
  O  O30  1  0.758  0.560  0.408  1.0
  O  O31  1  0.994  0.391  0.181  1.0
  O  O32  1  0.494  0.681  0.891  1.0
  O  O33  1  0.940  0.741  0.093  1.0
  O  O34  1  0.681  0.891  0.494  1.0
  O  O35  1  0.891  0.494  0.681  1.0
[/CIF]
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The material described by MgTiTa(PO4)3 crystallizes in the trigonal R3c space group. Mg(1) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form distorted MgO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra,  a faceface with one Ti(1)O6 octahedra, and  a faceface with one Ta(1)O6 octahedra. Ti(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form distorted TiO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and  a faceface with one Mg(1)O6 octahedra. Ta(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form TaO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and  a faceface with one Mg(1)O6 octahedra. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Ti(1)O6 octahedra, and corners with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-49°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ta(1) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Ti(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Ta(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgTaTi(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.595
_cell_length_b   8.595
_cell_length_c   8.595
_cell_angle_alpha   61.569
_cell_angle_beta   61.569
_cell_angle_gamma   61.569
_symmetry_Int_Tables_number   1
_cell_volume   464.796
_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
  Mg  Mg0  1  0.004  0.004  0.004  1.0
  Mg  Mg1  1  0.504  0.504  0.504  1.0
  Ta  Ta2  1  0.356  0.356  0.356  1.0
  Ta  Ta3  1  0.856  0.856  0.856  1.0
  Ti  Ti4  1  0.145  0.145  0.145  1.0
  Ti  Ti5  1  0.645  0.645  0.645  1.0
  P  P6  1  0.045  0.450  0.752  1.0
  P  P7  1  0.450  0.752  0.045  1.0
  P  P8  1  0.752  0.045  0.450  1.0
  P  P9  1  0.252  0.950  0.545  1.0
  P  P10  1  0.545  0.252  0.950  1.0
  P  P11  1  0.950  0.545  0.252  1.0
  O  O12  1  0.109  0.508  0.316  1.0
  O  O13  1  0.316  0.109  0.508  1.0
  O  O14  1  0.060  0.258  0.908  1.0
  O  O15  1  0.508  0.316  0.109  1.0
  O  O16  1  0.008  0.609  0.816  1.0
  O  O17  1  0.241  0.440  0.593  1.0
  O  O18  1  0.258  0.908  0.060  1.0
  O  O19  1  0.440  0.593  0.241  1.0
  O  O20  1  0.181  0.994  0.391  1.0
  O  O21  1  0.593  0.241  0.440  1.0
  O  O22  1  0.093  0.940  0.741  1.0
  O  O23  1  0.391  0.181  0.994  1.0
  O  O24  1  0.609  0.816  0.008  1.0
  O  O25  1  0.908  0.060  0.258  1.0
  O  O26  1  0.408  0.758  0.560  1.0
  O  O27  1  0.816  0.008  0.609  1.0
  O  O28  1  0.560  0.408  0.758  1.0
  O  O29  1  0.741  0.093  0.940  1.0
  O  O30  1  0.758  0.560  0.408  1.0
  O  O31  1  0.994  0.391  0.181  1.0
  O  O32  1  0.494  0.681  0.891  1.0
  O  O33  1  0.940  0.741  0.093  1.0
  O  O34  1  0.681  0.891  0.494  1.0
  O  O35  1  0.891  0.494  0.681  1.0
[/CIF]
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