The compound described by Na4MgY(PO4)3 crystallizes in the trigonal R3c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. Mg(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. Y(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form YO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. 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 and corners with two equivalent Y(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-37°. There are four inequivalent O sites. In the first O site, O(3) is bonded to one Na(2), two equivalent Na(1), one Mg(1), and one P(1) atom to form distorted face-sharing ONa3MgP trigonal bipyramids. In the second O site, O(4) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Y(1), and one P(1) atom. In the third O site, O(1) is bonded in a 2-coordinate geometry to one Na(1), one Mg(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a 2-coordinate geometry to one Na(1), one Y(1), and one P(1) atom. is represented by the CIF card [CIF]
data_Na4YMg(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.247
_cell_length_b   9.247
_cell_length_c   9.247
_cell_angle_alpha   60.033
_cell_angle_beta   60.033
_cell_angle_gamma   60.033
_symmetry_Int_Tables_number   1
_cell_volume   559.554
_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  0.348  0.348  0.348  1.0
  Mg  Mg1  1  0.848  0.848  0.848  1.0
  Na  Na2  1  0.886  0.619  0.239  1.0
  Na  Na3  1  0.619  0.239  0.886  1.0
  Na  Na4  1  0.239  0.886  0.619  1.0
  Na  Na5  1  0.386  0.739  0.119  1.0
  Na  Na6  1  0.739  0.119  0.386  1.0
  Na  Na7  1  0.119  0.386  0.739  1.0
  Na  Na8  1  0.495  0.495  0.495  1.0
  Na  Na9  1  0.995  0.995  0.995  1.0
  O  O10  1  0.519  0.119  0.279  1.0
  O  O11  1  0.119  0.279  0.519  1.0
  O  O12  1  0.279  0.519  0.119  1.0
  O  O13  1  0.019  0.779  0.619  1.0
  O  O14  1  0.779  0.619  0.019  1.0
  O  O15  1  0.619  0.019  0.779  1.0
  O  O16  1  0.475  0.893  0.718  1.0
  O  O17  1  0.893  0.718  0.475  1.0
  O  O18  1  0.718  0.475  0.893  1.0
  O  O19  1  0.975  0.218  0.393  1.0
  O  O20  1  0.218  0.393  0.975  1.0
  O  O21  1  0.393  0.975  0.218  1.0
  O  O22  1  0.433  0.225  0.581  1.0
  O  O23  1  0.225  0.581  0.433  1.0
  O  O24  1  0.581  0.433  0.225  1.0
  O  O25  1  0.933  0.081  0.725  1.0
  O  O26  1  0.081  0.725  0.933  1.0
  O  O27  1  0.725  0.933  0.081  1.0
  O  O28  1  0.579  0.780  0.406  1.0
  O  O29  1  0.780  0.406  0.579  1.0
  O  O30  1  0.406  0.579  0.780  1.0
  O  O31  1  0.079  0.906  0.280  1.0
  O  O32  1  0.906  0.280  0.079  1.0
  O  O33  1  0.280  0.079  0.906  1.0
  P  P34  1  0.555  0.955  0.245  1.0
  P  P35  1  0.955  0.245  0.555  1.0
  P  P36  1  0.245  0.555  0.955  1.0
  P  P37  1  0.055  0.745  0.455  1.0
  P  P38  1  0.745  0.455  0.055  1.0
  P  P39  1  0.455  0.055  0.745  1.0
  Y  Y40  1  0.652  0.652  0.652  1.0
  Y  Y41  1  0.152  0.152  0.152  1.0
[/CIF]
.
The compound described by Na4MgY(PO4)3 crystallizes in the trigonal R3c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. Mg(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. Y(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form YO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. 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 and corners with two equivalent Y(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-37°. There are four inequivalent O sites. In the first O site, O(3) is bonded to one Na(2), two equivalent Na(1), one Mg(1), and one P(1) atom to form distorted face-sharing ONa3MgP trigonal bipyramids. In the second O site, O(4) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Y(1), and one P(1) atom. In the third O site, O(1) is bonded in a 2-coordinate geometry to one Na(1), one Mg(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a 2-coordinate geometry to one Na(1), one Y(1), and one P(1) atom. is represented by the CIF card [CIF]
data_Na4YMg(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.247
_cell_length_b   9.247
_cell_length_c   9.247
_cell_angle_alpha   60.033
_cell_angle_beta   60.033
_cell_angle_gamma   60.033
_symmetry_Int_Tables_number   1
_cell_volume   559.554
_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  0.348  0.348  0.348  1.0
  Mg  Mg1  1  0.848  0.848  0.848  1.0
  Na  Na2  1  0.886  0.619  0.239  1.0
  Na  Na3  1  0.619  0.239  0.886  1.0
  Na  Na4  1  0.239  0.886  0.619  1.0
  Na  Na5  1  0.386  0.739  0.119  1.0
  Na  Na6  1  0.739  0.119  0.386  1.0
  Na  Na7  1  0.119  0.386  0.739  1.0
  Na  Na8  1  0.495  0.495  0.495  1.0
  Na  Na9  1  0.995  0.995  0.995  1.0
  O  O10  1  0.519  0.119  0.279  1.0
  O  O11  1  0.119  0.279  0.519  1.0
  O  O12  1  0.279  0.519  0.119  1.0
  O  O13  1  0.019  0.779  0.619  1.0
  O  O14  1  0.779  0.619  0.019  1.0
  O  O15  1  0.619  0.019  0.779  1.0
  O  O16  1  0.475  0.893  0.718  1.0
  O  O17  1  0.893  0.718  0.475  1.0
  O  O18  1  0.718  0.475  0.893  1.0
  O  O19  1  0.975  0.218  0.393  1.0
  O  O20  1  0.218  0.393  0.975  1.0
  O  O21  1  0.393  0.975  0.218  1.0
  O  O22  1  0.433  0.225  0.581  1.0
  O  O23  1  0.225  0.581  0.433  1.0
  O  O24  1  0.581  0.433  0.225  1.0
  O  O25  1  0.933  0.081  0.725  1.0
  O  O26  1  0.081  0.725  0.933  1.0
  O  O27  1  0.725  0.933  0.081  1.0
  O  O28  1  0.579  0.780  0.406  1.0
  O  O29  1  0.780  0.406  0.579  1.0
  O  O30  1  0.406  0.579  0.780  1.0
  O  O31  1  0.079  0.906  0.280  1.0
  O  O32  1  0.906  0.280  0.079  1.0
  O  O33  1  0.280  0.079  0.906  1.0
  P  P34  1  0.555  0.955  0.245  1.0
  P  P35  1  0.955  0.245  0.555  1.0
  P  P36  1  0.245  0.555  0.955  1.0
  P  P37  1  0.055  0.745  0.455  1.0
  P  P38  1  0.745  0.455  0.055  1.0
  P  P39  1  0.455  0.055  0.745  1.0
  Y  Y40  1  0.652  0.652  0.652  1.0
  Y  Y41  1  0.152  0.152  0.152  1.0
[/CIF]
.