The material described by KEr(PO3)4 crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(2), one O(3), one O(4), one O(6), and one O(9) atom. Er(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(2), one O(3), one O(4), one O(6), and one O(9) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(5), and one O(8) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(12), one O(3), one O(4), and one O(5) atom to form corner-sharing PO4 tetrahedra. In the third P site, P(3) is bonded to one O(11), one O(12), one O(6), and one O(7) atom to form corner-sharing PO4 tetrahedra. In the fourth P site, P(4) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form corner-sharing PO4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(11) is bonded in a distorted single-bond geometry to one K(1), one Er(1), and one P(3) atom. In the second O site, O(12) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one Er(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one K(1), one Er(1), and one P(1) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Er(1), and one P(2) atom. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), one Er(1), and one P(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the eighth O site, O(6) is bonded in a 1-coordinate geometry to one K(1), one Er(1), and one P(3) atom. In the ninth O site, O(7) is bonded in a bent 120 degrees geometry to one P(3) and one P(4) atom. In the tenth O site, O(8) is bonded in a bent 150 degrees geometry to one P(1) and one P(4) atom. In the eleventh O site, O(9) is bonded in a 2-coordinate geometry to one K(1), one Er(1), and one P(4) atom. In the twelfth O site, O(10) is bonded in a distorted single-bond geometry to one K(1), one Er(1), and one P(4) atom. is represented by the CIF file [CIF]
data_KEr(PO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.392
_cell_length_b   7.326
_cell_length_c   7.919
_cell_angle_alpha   88.550
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   486.721
_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
  K  K0  1  0.811  0.267  0.283  1.0
  K  K1  1  0.311  0.733  0.717  1.0
  Er  Er2  1  0.502  0.239  0.758  1.0
  Er  Er3  1  0.002  0.761  0.242  1.0
  P  P4  1  0.585  0.903  0.097  1.0
  P  P5  1  0.085  0.097  0.903  1.0
  P  P6  1  0.849  0.995  0.618  1.0
  P  P7  1  0.349  0.005  0.382  1.0
  P  P8  1  0.754  0.612  0.601  1.0
  P  P9  1  0.254  0.388  0.399  1.0
  P  P10  1  0.876  0.435  0.909  1.0
  P  P11  1  0.376  0.565  0.091  1.0
  O  O12  1  0.749  0.908  0.171  1.0
  O  O13  1  0.249  0.092  0.829  1.0
  O  O14  1  0.554  0.985  0.924  1.0
  O  O15  1  0.054  0.015  0.076  1.0
  O  O16  1  0.945  0.964  0.461  1.0
  O  O17  1  0.445  0.036  0.539  1.0
  O  O18  1  0.744  0.160  0.618  1.0
  O  O19  1  0.244  0.840  0.382  1.0
  O  O20  1  0.965  0.990  0.779  1.0
  O  O21  1  0.465  0.010  0.221  1.0
  O  O22  1  0.600  0.520  0.646  1.0
  O  O23  1  0.100  0.480  0.354  1.0
  O  O24  1  0.394  0.466  0.275  1.0
  O  O25  1  0.894  0.534  0.725  1.0
  O  O26  1  0.032  0.308  0.898  1.0
  O  O27  1  0.532  0.692  0.102  1.0
  O  O28  1  0.405  0.428  0.956  1.0
  O  O29  1  0.905  0.572  0.044  1.0
  O  O30  1  0.228  0.677  0.071  1.0
  O  O31  1  0.728  0.323  0.929  1.0
  O  O32  1  0.313  0.391  0.577  1.0
  O  O33  1  0.813  0.609  0.423  1.0
  O  O34  1  0.239  0.180  0.339  1.0
  O  O35  1  0.739  0.820  0.661  1.0
[/CIF]
.
The material described by KEr(PO3)4 crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(2), one O(3), one O(4), one O(6), and one O(9) atom. Er(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(2), one O(3), one O(4), one O(6), and one O(9) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(5), and one O(8) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(12), one O(3), one O(4), and one O(5) atom to form corner-sharing PO4 tetrahedra. In the third P site, P(3) is bonded to one O(11), one O(12), one O(6), and one O(7) atom to form corner-sharing PO4 tetrahedra. In the fourth P site, P(4) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form corner-sharing PO4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(11) is bonded in a distorted single-bond geometry to one K(1), one Er(1), and one P(3) atom. In the second O site, O(12) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one Er(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one K(1), one Er(1), and one P(1) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Er(1), and one P(2) atom. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), one Er(1), and one P(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the eighth O site, O(6) is bonded in a 1-coordinate geometry to one K(1), one Er(1), and one P(3) atom. In the ninth O site, O(7) is bonded in a bent 120 degrees geometry to one P(3) and one P(4) atom. In the tenth O site, O(8) is bonded in a bent 150 degrees geometry to one P(1) and one P(4) atom. In the eleventh O site, O(9) is bonded in a 2-coordinate geometry to one K(1), one Er(1), and one P(4) atom. In the twelfth O site, O(10) is bonded in a distorted single-bond geometry to one K(1), one Er(1), and one P(4) atom. is represented by the CIF file [CIF]
data_KEr(PO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.392
_cell_length_b   7.326
_cell_length_c   7.919
_cell_angle_alpha   88.550
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   486.721
_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
  K  K0  1  0.811  0.267  0.283  1.0
  K  K1  1  0.311  0.733  0.717  1.0
  Er  Er2  1  0.502  0.239  0.758  1.0
  Er  Er3  1  0.002  0.761  0.242  1.0
  P  P4  1  0.585  0.903  0.097  1.0
  P  P5  1  0.085  0.097  0.903  1.0
  P  P6  1  0.849  0.995  0.618  1.0
  P  P7  1  0.349  0.005  0.382  1.0
  P  P8  1  0.754  0.612  0.601  1.0
  P  P9  1  0.254  0.388  0.399  1.0
  P  P10  1  0.876  0.435  0.909  1.0
  P  P11  1  0.376  0.565  0.091  1.0
  O  O12  1  0.749  0.908  0.171  1.0
  O  O13  1  0.249  0.092  0.829  1.0
  O  O14  1  0.554  0.985  0.924  1.0
  O  O15  1  0.054  0.015  0.076  1.0
  O  O16  1  0.945  0.964  0.461  1.0
  O  O17  1  0.445  0.036  0.539  1.0
  O  O18  1  0.744  0.160  0.618  1.0
  O  O19  1  0.244  0.840  0.382  1.0
  O  O20  1  0.965  0.990  0.779  1.0
  O  O21  1  0.465  0.010  0.221  1.0
  O  O22  1  0.600  0.520  0.646  1.0
  O  O23  1  0.100  0.480  0.354  1.0
  O  O24  1  0.394  0.466  0.275  1.0
  O  O25  1  0.894  0.534  0.725  1.0
  O  O26  1  0.032  0.308  0.898  1.0
  O  O27  1  0.532  0.692  0.102  1.0
  O  O28  1  0.405  0.428  0.956  1.0
  O  O29  1  0.905  0.572  0.044  1.0
  O  O30  1  0.228  0.677  0.071  1.0
  O  O31  1  0.728  0.323  0.929  1.0
  O  O32  1  0.313  0.391  0.577  1.0
  O  O33  1  0.813  0.609  0.423  1.0
  O  O34  1  0.239  0.180  0.339  1.0
  O  O35  1  0.739  0.820  0.661  1.0
[/CIF]
.