Reinvestigation of KMg~1/3~Nb~2/3~OPO~4~
Babaryk, Artem A.; Bon, Vladimir; Zatovsky, Igor V.; Slobodyanik, Nikolay S.; Pekhnyo, Vasily; Acta Crystallographica Section E 66 (2010) i15–i16; doi:10.1107/S1600536810004617

data_2225167
_publ_section_title
;
 Reinvestigation of KMg~1/3~Nb~2/3~OPO~4~
;
_journal_coeditor_code           BR2136
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              i15
_journal_page_last               i16
_journal_paper_doi               10.1107/S1600536810004617
_journal_volume                  66
_journal_year                    2010
_chemical_formula_iupac          'K0.96 (Mg0.32 Nb0.68 O) (P O4)'
_chemical_formula_structural     'K0.96 (Mg0.32 Nb0.68 O) (P O4)'
_chemical_formula_sum            'K0.96 Mg0.32 Nb0.68 O5 P'
_chemical_formula_weight         219.46
_chemical_name_systematic
;
potassium magnesium niobium oxide phosphate
;
_space_group_IT_number           76
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4w'
_symmetry_space_group_name_H-M   'P 41'
_atom_sites_solution_primary     isomor
_atom_sites_solution_secondary   difmap
_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                   6.52610(10)
_cell_length_b                   6.52610(10)
_cell_length_c                   10.8427(4)
_cell_measurement_reflns_used    2061
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      30.5677
_cell_measurement_theta_min      3.1215
_cell_volume                     461.79(2)
_computing_cell_refinement       'SAINT (Bruker, 2007)'
_computing_data_collection       'APEX2 (Bruker, 2007)'
_computing_data_reduction        'SAINT (Bruker, 2007)'
_computing_molecular_graphics
'XP in SHELXTL (Sheldrick, 2008) and SLANT PLANE in WinGX (Farrugia, 1999)'
_computing_publication_material  'SHELXTL (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker APEXII'
_diffrn_measurement_method       '\f or \w oscillation scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0167
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            2467
_diffrn_reflns_reduction_process
;
Blessing, (1987)
Blessing, (1989)
;
_diffrn_reflns_theta_full        29.99
_diffrn_reflns_theta_max         29.99
_diffrn_reflns_theta_min         3.12
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    3.024
_exptl_absorpt_correction_T_max  0.746
_exptl_absorpt_correction_T_min  0.603
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
[SORTAV (Blessing, 1995) and SADABS (Bruker, 2007)]
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    3.158
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             420.4
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.3
_refine_diff_density_max         0.624
_refine_diff_density_min         -0.538
_refine_ls_abs_structure_details
;
Flack (1983), 336 Friedel pairs
;
_refine_ls_abs_structure_Flack   0.08(10)
_refine_ls_extinction_coef       0.0115(15)
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.196
_refine_ls_matrix_type           full
_refine_ls_number_parameters     107
_refine_ls_number_reflns         1036
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.195
_refine_ls_R_factor_all          0.0257
_refine_ls_R_factor_gt           0.0251
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+1.2901P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.0551
_reflns_number_gt                1020
_reflns_number_total             1036
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            br2136.cif
_cod_data_source_block           I
_cod_database_code               2225167
_cod_database_fobs_code          2225167