KMg(HP~2~O~7~).2H~2~O
El Bali, Brahim; Alaoui Tahiri, Aziz; Lachkar, Mohammed; Arriortua, Marcaida Isabel; Urtiaga, Miren Karmele; Acta Crystallographica, Section E 61 (2005) i275–i277; doi:10.1107/S1600536805036731

data_2207681
_publ_section_title
;
KMg(HP~2~O~7~).2H~2~O
;
_journal_coeditor_code           WM6097
_journal_issue                   12
_journal_name_full               'Acta Crystallographica, Section E'
_journal_page_first              i275
_journal_page_last               i277
_journal_paper_doi               10.1107/S1600536805036731
_journal_volume                  61
_journal_year                    2005
_chemical_compound_source        Synthetic
_chemical_formula_iupac          'K Mg (H P2 O7) (H2 O)2'
_chemical_formula_structural     'K [Mg (H P2 O7) (H2 O)2]'
_chemical_formula_sum            'H5 K Mg O9 P2'
_chemical_formula_weight         274.39
_chemical_name_systematic
;
potassium magnesium hydrogendiphosphate dihydrate
;
_space_group_IT_number           62
_space_group_name_Hall           '-P 2ac 2n'
_space_group_name_H-M_alt        'P n m a'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2n'
_symmetry_space_group_name_H-M   'P n m a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.2
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   15.5203(13)
_cell_length_b                   7.7786(6)
_cell_length_c                   6.4822(5)
_cell_measurement_reflns_used    3218
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      31.825
_cell_measurement_theta_min      3.136
_cell_volume                     782.57(11)
_computing_cell_refinement
;
CrysAlis RED (Oxford Diffraction, 2004)
;
_computing_data_collection
;
CrysAlis CCD (Oxford Diffraction, 2004)
;
_computing_data_reduction
;
CrysAlis RED
;
_computing_molecular_graphics
;
ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2003)
;
_computing_publication_material
;
WinGX (Farrugia, 1999)
;
_computing_structure_refinement
;
SHELXL97 (Sheldrick, 1997)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 1997)
;
_database_code_amcsd             0010468
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.944
_diffrn_measured_fraction_theta_max 0.944
_diffrn_measurement_device_type  'Oxford XCALIBUR-2 CCD'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0297
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            6826
_diffrn_reflns_theta_full        31.89
_diffrn_reflns_theta_max         31.89
_diffrn_reflns_theta_min         3.41
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.191
_exptl_absorpt_correction_T_max  0.8253
_exptl_absorpt_correction_T_min  0.75437
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   '(CrysAlis RED; Oxford Diffraction, 2004)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.329
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             552
_exptl_crystal_size_max          0.145
_exptl_crystal_size_mid          0.118
_exptl_crystal_size_min          0.097
_refine_diff_density_max         0.458
_refine_diff_density_min         -0.536
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.054
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     77
_refine_ls_number_reflns         1353
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.055
_refine_ls_R_factor_all          0.0369
_refine_ls_R_factor_gt           0.0330
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0498P)^2^] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0862
_refine_ls_wR_factor_ref         0.0886
_reflns_number_gt                1173
_reflns_number_total             1353
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            wm6097.cif
_cod_database_code               2207681
_amcsd_formula_title             KMg(HP2O7)*2H2O