K2Fe2B2O7: A transparent nonlinear optical crystal with frustrated magnetism
Wang, Yonggang; Li, R.K.; Journal of Solid State Chemistry 183 (2010) 1221–1225; doi:10.1016/j.jssc.2010.03.037

data_1563562
_publ_section_title
;
 K2Fe2B2O7: A transparent nonlinear optical crystal with frustrated
 magnetism
;
_journal_issue                   6
_journal_name_full               'Journal of Solid State Chemistry'
_journal_page_first              1221
_journal_page_last               1225
_journal_paper_doi               10.1016/j.jssc.2010.03.037
_journal_volume                  183
_journal_year                    2010
_chemical_formula_sum            'B2 Fe2 K2 O7'
_chemical_formula_weight         323.52
_chemical_melting_point          1014
_space_group_IT_number           150
_space_group_name_Hall           'P 3 2"'
_space_group_name_H-M_alt        'P 3 2 1'
_symmetry_cell_setting           hexagonal
_symmetry_space_group_name_H-M   'P 3 2 1'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            3
_cell_length_a                   8.7475(12)
_cell_length_b                   8.7475(12)
_cell_length_c                   8.5124(17)
_cell_measurement_reflns_used    2093
_cell_measurement_temperature    93(2)
_cell_measurement_theta_max      27.4662
_cell_measurement_theta_min      3.6004
_cell_volume                     564.09(16)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      93(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0563
_diffrn_reflns_av_sigmaI/netI    0.0397
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            4534
_diffrn_reflns_theta_full        27.47
_diffrn_reflns_theta_max         27.47
_diffrn_reflns_theta_min         3.60
_exptl_absorpt_coefficient_mu    4.957
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.7335
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'CrystalClear.Rigaku Corporation.(1997-2002)'
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    2.857
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Chunk
_exptl_crystal_F_000             468
_exptl_crystal_size_max          0.167
_exptl_crystal_size_mid          0.167
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.495
_refine_diff_density_min         -0.672
_refine_diff_density_rms         0.130
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.03(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.984
_refine_ls_matrix_type           full
_refine_ls_number_parameters     61
_refine_ls_number_reflns         874
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.984
_refine_ls_R_factor_all          0.0282
_refine_ls_R_factor_gt           0.0240
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0207P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0523
_refine_ls_wR_factor_ref         0.0540
_reflns_number_gt                779
_reflns_number_total             874
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            JSSC-2010-183-1221.cif
_cod_data_source_block           br173
_cod_original_sg_symbol_H-M      P321
_cod_database_code               1563562