data_K2SO4

_chemical_name_systematic          'Potassium sulfate - high-temperature phase'
_chemical_formula_structural       'K2 S O4'
_chemical_formula_sum              'K2 O4 S'

_publ_section_title                
;
Structure Reinvestigation of the High-Temperature Form of K~2~ S O~4~
;
loop_
_publ_author_name                  
  'Miyake, M'
  'Morikawa, H'
  'Iwai, S I'
_journal_name_full                 'Acta Crystallographica B (24,1968-38,1982)'
_journal_coden_ASTM                ACBCAR
_journal_volume                    36
_journal_year                      1980
_journal_page_first                532
_journal_page_last                 536

_cell_length_a                     5.947(2)
_cell_length_b                     5.947(2)
_cell_length_c                     8.375(3)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  120
_cell_volume                       256.5
_cell_formula_units_Z              2

_exptl_crystal_density_meas        2.26

_symmetry_space_group_name_H-M     'P 63/m m c'
_symmetry_Int_Tables_number        194
_symmetry_cell_setting             hexagonal

loop_
_symmetry_equiv_pos_as_xyz         
  'x,y,z'
  '-y,x-y,z'
  'y-x,-x,z'
  '-y,-x,z'
  'y-x,y,z'
  'x,x-y,z'
  '-x,-y,-z'
  'y,y-x,-z'
  'x-y,x,-z'
  'y,x,-z'
  'x-y,-y,-z'
  '-x,y-x,-z'
  '-x,-y,1/2+z'
  'y,y-x,1/2+z'
  'x-y,x,1/2+z'
  'y,x,1/2+z'
  'x-y,-y,1/2+z'
  '-x,y-x,1/2+z'
  'x,y,1/2-z'
  '-y,x-y,1/2-z'
  'y-x,-x,1/2-z'
  '-y,-x,1/2-z'
  'y-x,y,1/2-z'
  'x,x-y,1/2-z'

loop_
_atom_type_symbol
_atom_type_oxidation_number
  K1+    1.000
  S6+    6.000
  O2-   -2.000

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  K1    K1+    2 a 0. 0. 0. 1.  0 d
  K2    K1+    2 d 0.6667 0.3333 0.25 1.  0 d
  S1    S6+    2 c 0.3333 0.6667 0.25 1.  0 d
  O1    O2-    4 f 0.3333 0.6667 0.410(5) 1.  0 d
  O2    O2-   12 k 0.212(2) -0.212(2) 0.188(3) 0.333  0 d

_refine_ls_R_factor_all            0.086



data_K2SO4 - II

_chemical_name_systematic          'Potassium sulfate - $-beta'
_chemical_formula_structural       'K2 S O4'
_chemical_formula_sum              'K2 O4 S'

_publ_section_title                
;
The crystal structures of $-beta-K~2~ S O~4~ and of $-beta K~2~ P O~3~ F
;
_publ_author_name                  'Robinson, M T'
_journal_name_full                 'Journal of Physical Chemistry'
_journal_coden_ASTM                JPCHAX
_journal_volume                    62
_journal_year                      1958
_journal_page_first                925
_journal_page_last                 928

_cell_length_a                     7.456(6)
_cell_length_b                     10.08(1)
_cell_length_c                     5.776(5)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       434.1
_cell_formula_units_Z              4

_exptl_crystal_density_meas        2.62(0)

_symmetry_space_group_name_H-M     'P n a m'
_symmetry_Int_Tables_number        62
_symmetry_cell_setting             orthorhombic

loop_
_symmetry_equiv_pos_as_xyz         
  'x,y,z'
  '1/2+x,1/2-y,1/2-z'
  '-x,-y,1/2+z'
  '1/2-x,1/2+y,-z'
  '-x,-y,-z'
  '1/2-x,1/2+y,1/2+z'
  'x,y,1/2-z'
  '1/2+x,1/2-y,z'

loop_
_atom_type_symbol
_atom_type_oxidation_number
  K1+    1.000
  S6+    6.000
  O2-   -2.000

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  K1    K1+    4 c 0.1768(25) 0.0818(128) 0.25 1.  0 d
  K2    K1+    4 c -0.0115(19) 0.7046(15) 0.25 1.  0 d
  S1    S6+    4 c 0.2358(36) 0.4155(161) 0.25 1.  0 d
  O1    O2-    4 c 0.0315(74) 0.4032(87) 0.25 1.  0 d
  O2    O2-    4 c 0.2970(89) 0.5579(44) 0.25 1.  0 d
  O3    O2-    8 d 0.2997(46) 0.3484(28) 0.0410(41) 1.  0 d

_refine_ls_R_factor_all            0.095



data_K2SO4 III

_chemical_name_systematic          'Potassium sulfate(VI)'
_chemical_formula_structural       'K2 (S O4)'
_chemical_formula_sum              'K2 O4 S'

_publ_section_title                
;
Structure of potassium sulfate at temperatures from 296K down to 15K
;
loop_
_publ_author_name                  
  'Ojima, K'
  'Nishihata, Y'
  'Sawada, A'
_journal_name_full                 'Acta Crystallographica B (39,1983-)'
_journal_coden_ASTM                ASBSDK
_journal_volume                    51
_journal_year                      1995
_journal_page_first                287
_journal_page_last                 293

_cell_length_a                     5.7704(3)
_cell_length_b                     10.0712(9)
_cell_length_c                     7.4776(4)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       434.6
_cell_formula_units_Z              4

_symmetry_space_group_name_H-M     'P m c n'
_symmetry_Int_Tables_number        62
_symmetry_cell_setting             orthorhombic

loop_
_symmetry_equiv_pos_as_xyz         
  'x,y,z'
  '1/2-x,1/2-y,1/2+z'
  '1/2+x,-y,-z'
  '-x,1/2+y,1/2-z'
  '-x,-y,-z'
  '1/2+x,1/2+y,1/2-z'
  '1/2-x,y,z'
  'x,1/2-y,1/2+z'

loop_
_atom_type_symbol
_atom_type_oxidation_number
  K1+    1.000
  S6+    6.000
  O2-   -2.000

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  K1    K1+    4 c 0.25 0.08935(6) 0.17398(7) 1.  0 d
  K2    K1+    4 c 0.25 0.79550(5) 0.48915(7) 1.  0 d
  S1    S6+    4 c 0.25 0.41985(5) 0.23295(7) 1.  0 d
  O1    O2-    4 c 0.25 0.4162(3) 0.0368(3) 1.  0 d
  O2    O2-    4 c 0.25 0.5585(2) 0.2976(3) 1.  0 d
  O3    O2-    8 d 0.0412(3) 0.3522(2) 0.3017(2) 1.  0 d

loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_22
_atom_site_aniso_U_23
_atom_site_aniso_U_33
  K1    0.0169(2) 0. 0. 0.0197(2) 0.0006(2) 0.0164(2)
  K2    0.0185(2) 0. 0. 0.0150(1) -0.0005(1) 0.0132(1)
  S1    0.0101(1) 0. 0. 0.0095(1) -0.0005(1) 0.0101(1)
  O1    0.0382(1) 0. 0. 0.0318(10) -0.0019(7) 0.0089(5)
  O2    0.0254(8) 0. 0. 0.0120(6) -0.0044(5) 0.0210(7)
  O3    0.0140(4) -0.0063(4) 0.0032(5) 0.0227(5) 0.0052(5) 0.0298(6)

_refine_ls_R_factor_all            0.036