Centrosymmetric aliovalent KTP isomorphs K<i>M</i>^III^~0.5~Nb~0.5~OPO~4~ (<i>M</i> = Cr and Fe)
Artem A. Babaryk; Igor V. Zatovsky; Vyacheslav N. Baumer; Nikolay S. Slobodyanik; Oleg V. Shishkin; Acta Crystallographica Section C 62 (2006) i91–i93; doi:10.1107/S0108270106028678

data_2015649
_publ_section_title
;
 Centrosymmetric aliovalent KTP isomorphs
 K<i>M</i>^III^~0.5~Nb~0.5~OPO~4~ (<i>M</i> = Cr and Fe)
;
_journal_coeditor_code           IZ3009
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              i91
_journal_page_last               i93
_journal_paper_doi               10.1107/S0108270106028678
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'K Fe0.5 Nb0.5 O P O4'
_chemical_formula_moiety         'K +, Fe0.5 Nb0.5 O5 P1 -'
_chemical_formula_sum            'Fe0.5 K Nb0.5 O5 P'
_chemical_formula_weight         224.45
_chemical_name_systematic
;
potassium iron niobium oxide phosphate
;
_space_group_IT_number           52
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2a 2bc'
_symmetry_space_group_name_H-M   'P n n a'
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   12.9675(13)
_cell_length_b                   10.705(3)
_cell_length_c                   6.4638(7)
_cell_measurement_reflns_used    450
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      26
_cell_measurement_theta_min      15
_cell_volume                     897.3(3)
_computing_cell_refinement       'CrysAlis CCD'
_computing_data_collection       'CrysAlis CCD (Oxford Diffraction, 2005)'
_computing_data_reduction        'CrysAlis RED (Oxford Diffraction, 2005)'
_computing_molecular_graphics
'Ortep-3 for Windows (Farrugia, 1997) and DIAMOND Bradenburg, 2006)'
_computing_publication_material  'WinGX (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1
_diffrn_measured_fraction_theta_max 1
_diffrn_measurement_device_type  'Oxford Diffraction XCalibur-3'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0272
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            18570
_diffrn_reflns_theta_full        27.98
_diffrn_reflns_theta_max         27.98
_diffrn_reflns_theta_min         3.14
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    4.219
_exptl_absorpt_correction_T_max  0.4956
_exptl_absorpt_correction_T_min  0.3871
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(Blessing, 1995)
;
_exptl_crystal_colour            dark_red
_exptl_crystal_density_diffrn    3.323
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             860
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.1
_refine_diff_density_max         1.468
_refine_diff_density_min         -1.323
_refine_ls_extinction_coef       0.0048(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.326
_refine_ls_matrix_type           full
_refine_ls_number_parameters     88
_refine_ls_number_reflns         1087
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.325
_refine_ls_R_factor_gt           0.0482
_refine_ls_shift/su_max          0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0000P)^2^+22.5550P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1125
_reflns_number_gt                1021
_reflns_number_total             1087
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            iz3009.cif
_cod_data_source_block           II
_cod_original_formula_sum        'Fe0.50 K Nb0.50 O5 P'
_cod_database_code               2015649
_cod_database_fobs_code          2015649