Strontium Diiron(III) Pyrophosphate
Boutfessi, A.; Boukhari, A.; Holt, E. M.; Acta Crystallographica Section C 51 (1995) 346–348; doi:10.1107/S0108270194010693

data_2003248
_publ_section_title
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 Strontium Diiron(III) Pyrophosphate
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_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              346
_journal_page_last               348
_journal_paper_doi               10.1107/S0108270194010693
_journal_volume                  51
_journal_year                    1995
_chemical_compound_source
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SrFe(III)~2~(P~2~O~7~)~2~ has been synthesized by
mixing stoichiometric amounta of (NH~4~)~2~HPO~4~, SrCO~3~ and
Fe~2~O~3~ according to the following equation:
SrCO~3~ + 4(NH~4~)~2~HPO~4~ + Fe~2~O~3~ => SrFe~2~(P~2~O~7~)~2~ +
8NH~3~ + CO~2~ + 6H~2~O
After grinding, the mixture was heated progressively to 1243 K. The final
heating was followed by a return to room temperature in air.
Single crystals were prepared by grinding and heating an
appropriate mixture of material to 1275 K.
After 24 h at this temperature, the melt was cooled  (5 K h^-1^)
allowing the isolation of grey crystals.
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_chemical_formula_moiety         'Fe2 O14 P4 Sr1'
_chemical_formula_sum            'Fe2 O14 P4 Sr'
_chemical_formula_weight         547.2
_chemical_name_systematic
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Strontium Iron(III) Diphosphate
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_cell_angle_alpha                89.83(3)
_cell_angle_beta                 87.59(3)
_cell_angle_gamma                73.11(3)
_cell_formula_units_Z            1
_cell_length_a                   4.795(1)
_cell_length_b                   7.108(1)
_cell_length_c                   7.830(2)
_cell_measurement_reflns_used    45
_cell_measurement_temperature    298
_cell_measurement_theta_max      17.0
_cell_measurement_theta_min      10.0
_cell_volume                     255.12(10)
_computing_cell_refinement       'XSCANS (Siemens, 1991)'
_computing_data_collection       'XSCANS (Siemens, 1991)'
_computing_data_reduction        'XSCANS (Siemens, 1991)'
_computing_molecular_graphics    'XP (Siemens, 1991)'
_computing_structure_refinement  'SHELXS86 (Sheldrick, 1990)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      298
_diffrn_measurement_device       'Syntex P4 4-circle'
_diffrn_measurement_method       \q/2\q
_diffrn_radiation_monochromator  'highly oriented graphite crystal'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0178
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -1
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            1966
_diffrn_reflns_theta_max         30
_diffrn_reflns_theta_min         1.75
_diffrn_standards_decay_%        0.0001
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    8.731
_exptl_absorpt_correction_T_max  0.37
_exptl_absorpt_correction_T_min  0.12
_exptl_absorpt_correction_type   semi-empirical
_exptl_crystal_colour            grey
_exptl_crystal_density_diffrn    3.561
_exptl_crystal_description       chunk
_exptl_crystal_F_000             262
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.3
_exptl_crystal_thermal_history
;heated progressively to 1243 K; heating an appropriate mixture of material to
 1275 K
;
_refine_diff_density_max         1.41
_refine_diff_density_min         -0.85
_refine_ls_goodness_of_fit_obs   1.13
_refine_ls_matrix_type           full
_refine_ls_number_parameters     101
_refine_ls_number_reflns         1247
_refine_ls_R_factor_obs          .0378
_refine_ls_shift/esd_max         0.001
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     'w = 1/[\s^2^(F)+ 0.0008F^2^]'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         .0463
_reflns_number_observed          1247
_reflns_number_total             1483
_reflns_observed_criterion       F>4.0\s(F)
_cod_data_source_file            br1094.cif
_cod_data_source_block           holt_compound_1
_cod_depositor_comments
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The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'w = 1/[\s^2^(F)+ 0.0008F^2^]'
was changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w = 1/[\s^2^(F)+
0.0008F^2^]'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        255.13(9)
_cod_original_formula_sum        'Fe2 O14 P4 Sr1'
_cod_database_code               2003248