Crystal structure of apatite type Ca~2.49~Nd~7.51~(SiO~4~)~6~O~1.75~
Le, Thu Hoai; Brooks, Neil R.; Binnemans, Koen; Blanpain, Bart; Guo, Muxing; Van Meervelt, Luc; Acta Crystallographica Section E 72 (2016) 209–211; doi:10.1107/S205698901600089X

data_2241479
_publ_section_title
;
 Crystal structure of apatite type Ca~2.49~Nd~7.51~(SiO~4~)~6~O~1.75~
;
_journal_coeditor_code           RU2066
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              209
_journal_page_last               211
_journal_paper_doi               10.1107/S205698901600089X
_journal_volume                  72
_journal_year                    2016
_chemical_formula_iupac          'Ca2.49 Nd7.51 (Si O4)6 O1.75'
_chemical_formula_moiety         'Ca2.49 Nd7.51 O25.75 Si6'
_chemical_formula_sum            'Ca2.49 Nd7.51 O25.75 Si6'
_chemical_formula_weight         1763.24
_chemical_name_systematic
;
Dicalcium octaneodymium hexakis(orthosilicate) dioxide
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           176
_space_group_name_Hall           '-P 6c'
_space_group_name_H-M_alt        'P 63/m'
_symmetry_space_group_name_Hall  '-P 6c'
_symmetry_space_group_name_H-M   'P 63/m'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method
;
Olex2 1.2-alpha
(compiled 2014.05.21 svn.r2940 for OlexSys, GUI svn.r4844)
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            1
_cell_length_a                   9.5507(3)
_cell_length_b                   9.5507(3)
_cell_length_c                   7.0513(3)
_cell_measurement_reflns_used    1649
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      35.4880
_cell_measurement_theta_min      4.2480
_cell_volume                     557.02(3)
_computing_cell_refinement
;
CrysAlisPro (Agilent, 2012)
;
_computing_data_collection
;
CrysAlisPro (Agilent, 2012)
;
_computing_data_reduction
;
CrysAlisPro (Agilent, 2012)
;
_computing_molecular_graphics
;
<i>OLEX2</i> (Dolomanov <i>et al.</i>,  2009)
;
_computing_publication_material
;
<i>OLEX2</i> (Dolomanov <i>et al.</i>,  2009) and publCIF (Westrip,
2010)
;
_computing_structure_refinement
;
SHELXL2014 (Sheldrick, 2015)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 2008)
;
_diffrn_ambient_temperature      298(2)
_diffrn_detector_area_resol_mean 15.9631
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.953
_diffrn_measurement_device_type
;
Agilent SuperNova (single source at offset, Eos detector)
;
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0239
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            2616
_diffrn_reflns_theta_full        30.00
_diffrn_reflns_theta_max         35.69
_diffrn_reflns_theta_min         3.80
_exptl_absorpt_coefficient_mu    18.176
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.717
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(CrysAlis PRO; Agilent, 2012)
;
_exptl_crystal_colour            'light blue'
_exptl_crystal_density_diffrn    5.256
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             790
_exptl_crystal_size_max          0.05
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.791
_refine_diff_density_min         -0.861
_refine_ls_extinction_coef       0.0062(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method
;
SHELXL2014 (Sheldrick, 2015)
;
_refine_ls_goodness_of_fit_ref   1.108
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_constraints    4
_refine_ls_number_parameters     42
_refine_ls_number_reflns         878
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.108
_refine_ls_R_factor_all          0.0215
_refine_ls_R_factor_gt           0.0186
_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^)+(0.0072P)^2^+0.3232P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0339
_refine_ls_wR_factor_ref         0.0348
_reflns_number_gt                813
_reflns_number_total             878
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ru2066sup1.cif
_cod_data_source_block           I
_cod_original_cell_volume        557.03(3)
_cod_database_code               2241479
_cod_database_fobs_code 2241479