Strontium magnesium phosphate, Sr~2+<i>x~</i>Mg~3{-~<i>x</i>}P~4~O~15~ (<i>x</i> σim 0.36), from laboratory X-ray powder data
Hong, Jung-Hwa; Song, Seung-Wan; Hong, Seung-Tae; Acta Crystallographica Section C 67 (2011) i1–i3; doi:10.1107/S0108270110047967

data_2017952
_publ_section_title
;
 Strontium magnesium phosphate, Sr~2+<i>x~</i>Mg~3{-~<i>x</i>}P~4~O~15~
 (<i>x</i> \sim 0.36), from laboratory X-ray powder data
;
_journal_coeditor_code           SQ3270
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              i1
_journal_page_last               i3
_journal_paper_doi               10.1107/S0108270110047967
_journal_volume                  67
_journal_year                    2011
_chemical_formula_iupac          'Mg2 P2 O7'
_chemical_formula_moiety         'Mg2 O7 P2'
_chemical_formula_sum            'Mg2 O7 P2'
_chemical_formula_weight         222.56
_chemical_name_systematic
;
dimagnesium heptaoxidodiphosphate
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_cell_angle_alpha                90.0
_cell_angle_beta                 113.816(3)
_cell_angle_gamma                90.0
_cell_formula_units_Z            4
_cell_length_a                   6.9443(4)
_cell_length_b                   8.2861(4)
_cell_length_c                   9.0438(5)
_cell_measurement_temperature    296
_cell_volume                     476.08(5)
_computing_cell_refinement       'GSAS (Larson & Von Dreele, 2000)'
_computing_data_collection       'COMMANDER (Bruker, 2003)'
_computing_data_reduction        'EVA (Bruker, 2003)'
_computing_molecular_graphics    'ATOMS (Dowty, 2000)'
_computing_publication_material  'GSAS (Larson & Von Dreele, 2000)'
_computing_structure_refinement  'GSAS (Larson & Von Dreele, 2000)'
_computing_structure_solution
'SHELXS (Sheldrick, 2008) and CRYSTALS (Betteridge <i>et al.</i>, 2003)'
_diffrn_ambient_temperature      296
_diffrn_measurement_device_type  'Bruker D8 Advance'
_diffrn_radiation_monochromator  'Ge 111'
_diffrn_radiation_type           'Cu K\a~1~'
_diffrn_radiation_wavelength     1.5406
_exptl_crystal_density_diffrn    3.105
_exptl_crystal_F_000             440.0
_pd_block_id                     2010-08-25T23:07|SMPO_phase2|Jung-Hwa_Hong||
_pd_char_colour                  white
_pd_meas_2theta_range_inc        0.016682
_pd_meas_2theta_range_max        140.42172
_pd_meas_2theta_range_min        8.0
_pd_meas_number_of_points        7939
_pd_meas_scan_method             step
_pd_prep_temperature             296
_pd_proc_ls_background_function
;   GSAS Background function number 1 with 36 terms.
 Shifted Chebyshev function of 1st kind
      1:    667.815     2:   -121.026     3:    250.928     4:   -108.029
      5:    130.095     6:   -120.393     7:    81.5238     8:   -66.4354
      9:    31.4946    10:   -19.2674    11:    16.0150    12:   -21.1906
     13:    24.6787    14:   -7.73173    15:    5.82669    16:    7.16351
     17:    9.66948    18:    8.02466    19:    5.65618    20:    4.74674
     21:   -11.8793    22:  -0.873263    23:   -2.40368    24:   -9.55052
     25:   -6.36605    26:    6.28370    27:   -8.07052    28:    6.33955
     29:   -12.6008    30:    3.68005    31:    5.95000    32:    7.62516
     33:    1.58465    34:    5.63269    35:   -2.90398    36:    14.7130
;
_pd_proc_ls_peak_cutoff          0.00200
_pd_proc_ls_profile_function
;
CW Profile function number 4 with  21 terms
Pseudovoigt profile coefficients as parameterized in
Thompson <i>et al.</i>
[Thompson, P., Cox, D. E. & Hastings, J. B. (1987). <i>J. Appl.
Cryst.</i> <b>20</b>, 79--83].
Asymmetry correction of Finger <i>et al.</i>
[Finger, L. W., Cox, D. E. & Jephcoat, A. P. (1994). <i>J. Appl.
Cryst.</i> <b>27</b>, 892--900].
Microstrain broadening by Stephens
[Stephens, P. W. (1999). <i>J. Appl. Cryst.</i> <b>32</b>, 281--289].
Peak tails are ignored  where the intensity is below 0.0020 times the peak
 Aniso. broadening axis   0.0   0.0   1.0
;
_pd_proc_ls_prof_R_factor        0.0478
_pd_proc_ls_prof_wR_expected     0.0254
_pd_proc_ls_prof_wR_factor       0.0631
_pd_spec_mounting                'packed powder pellet'
_pd_spec_mount_mode              reflection
_pd_spec_shape                   flat_sheet
_pd_spec_size_axial              20
_pd_spec_size_equat              20
_pd_spec_size_thick              1
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   2.50
_refine_ls_matrix_type           full
_refine_ls_number_parameters     81
_refine_ls_number_reflns         981
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0469
_refine_ls_shift/su_max          0.02
_refine_ls_shift/su_mean         0.00
_refine_ls_weighting_scheme      sigma
_cod_data_source_file            sq3270.cif
_cod_data_source_block           phase_2
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2017952
_cod_database_fobs_code          2017952