Ba~1.01~Sr~0.99~P~2~O~7~: un nouveau site Ba^2+^ révélé par diffraction des rayons X
Edhokkar, Fadhila; Hadrich, Ahmed; Graia, Mohsen; Mhiri, Tahar; Acta Crystallographica Section C 68 (2012) i86–i88; doi:10.1107/S0108270112047002

data_2018698
_publ_section_title
;
 Ba~1.01~Sr~0.99~P~2~O~7~: un nouveau site Ba^2+^ r\'ev\'el\'e par
 diffraction des rayons X
;
_journal_coeditor_code           BI3047
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              i86
_journal_page_last               i88
_journal_paper_doi               10.1107/S0108270112047002
_journal_volume                  68
_journal_year                    2012
_chemical_formula_iupac          'Ba1.01 Sr0.99 P2 O7'
_chemical_formula_moiety         'Ba1.01 Sr0.99 P2 O7'
_chemical_formula_sum            'Ba1.01 O7 P2 Sr0.99'
_chemical_formula_weight         399.52
_chemical_name_common            'Barium strontium phosphate'
_chemical_name_systematic
;
Barium strontium diphosphate
;
_space_group_IT_number           62
_space_group_name_Hall           '-P 2bc 2a'
_space_group_name_H-M_alt        'P m n b'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2bc 2a'
_symmetry_space_group_name_H-M   'P m n b'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.5810(2)
_cell_length_b                   9.2020(2)
_cell_length_c                   13.5610(2)
_cell_measurement_reflns_used    838
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      14.92
_cell_measurement_theta_min      11.39
_cell_volume                     696.44(3)
_computing_cell_refinement       'CAD-4 EXPRESS (Enraf--Nonius, 1995)'
_computing_data_collection       'CAD-4 EXPRESS (Enraf--Nonius, 1995)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'DIAMOND (Brandenburg, 2001)'
_computing_publication_material
;
WinGX (Farrugia, 1999) and publCIF (Westrip, 2010)
;
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Enraf--Nonius CAD-4'
_diffrn_measurement_method       \w/2\q
_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  0.0232
_diffrn_reflns_av_sigmaI/netI    0.0213
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -1
_diffrn_reflns_limit_l_max       1
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            1852
_diffrn_reflns_theta_full        26.95
_diffrn_reflns_theta_max         26.95
_diffrn_reflns_theta_min         2.67
_diffrn_standards_decay_%        4
_diffrn_standards_interval_time  120
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    13.725
_exptl_absorpt_correction_T_max  0.312
_exptl_absorpt_correction_T_min  0.101
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(North <i>et al.</i>, 1968)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    3.804
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             720
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.711
_refine_diff_density_min         -0.841
_refine_ls_extinction_coef       0.0017(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 2008)'
_refine_ls_goodness_of_fit_ref   1.143
_refine_ls_matrix_type           full
_refine_ls_number_parameters     71
_refine_ls_number_reflns         838
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.142
_refine_ls_R_factor_all          0.0185
_refine_ls_R_factor_gt           0.0170
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0186P)^2^+0.5519P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0396
_refine_ls_wR_factor_ref         0.0400
_reflns_number_gt                800
_reflns_number_total             838
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bi3047.cif
_cod_data_source_block           I
_cod_original_formula_sum        'Ba1.01 Sr0.99 P2 O7'
_cod_database_code               2018698
_cod_database_fobs_code          2018698