Structure and complex twinning of dysprosium disilicate (Dy~2~Si~2~O~7~), Type B
Fleet, Michael E.; Liu, Xiaoyang; Acta Crystallographica Section B 56 (2000) 940–946; doi:10.1107/S0108768100008545

data_2102185
_publ_section_title
;
 Structure and complex twinning of dysprosium disilicate
 (Dy~2~Si~2~O~7~), Type B
;
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              940
_journal_page_last               946
_journal_paper_doi               10.1107/S0108768100008545
_journal_volume                  56
_journal_year                    2000
_chemical_compound_source
;
hydrothermal synthesis, 0.10 GPa, 1008 K
;
_chemical_formula_moiety         'Dy2 Si2 O7'
_chemical_formula_structural     '[Dy~2~Si~2~O~7~]'
_chemical_formula_sum            'Dy2 O7 Si2'
_chemical_formula_weight         493.17
_chemical_name_common            'dysprosium disilicate'
_chemical_name_systematic        'dysprosium disilicate'
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                94.373(2)
_cell_angle_beta                 90.836(2)
_cell_angle_gamma                91.512(2)
_cell_formula_units_Z            4
_cell_length_a                   6.6158(2)
_cell_length_b                   6.6604(2)
_cell_length_c                   12.0551(4)
_cell_measurement_reflns_used    32768
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      35
_cell_measurement_theta_min      2
_cell_volume                     529.39(3)
_computing_cell_refinement       'COLLECT (Nonius, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1997)'
_computing_data_reduction        'SUNY Buffalo DATAP77'
_computing_structure_refinement  'SUNY Buffalo LINEX77'
_computing_structure_solution    'SHELXTL PC Siemens'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'Nonius KappaCCD diffractometer'
_diffrn_measurement_method       'area detector and scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.70926
_diffrn_reflns_av_R_equivalents  0.107
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            32768
_diffrn_reflns_theta_max         35
_diffrn_reflns_theta_min         2
_exptl_absorpt_coefficient_mu    28.45
_exptl_absorpt_correction_T_max  0.380
_exptl_absorpt_correction_T_min  0.144
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
(Coppens, Leiserowitz & Rabinovich, 1965) 
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    6.156
_exptl_crystal_description       prism
_exptl_crystal_size_max          0.11
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.05
_refine_diff_density_max         4.65
_refine_diff_density_min         -4.70
_refine_ls_extinction_coef       0.31(2)
_refine_ls_extinction_expression
;
Coppens & Hamilton (1970)
;
_refine_ls_extinction_method
;
B-C type 1 Lorentzian isotropic
;
_refine_ls_goodness_of_fit_ref   0.978
_refine_ls_matrix_type           full
_refine_ls_number_parameters     204
_refine_ls_number_reflns         4470
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.1313
_refine_ls_R_factor_gt           0.0325
_refine_ls_shift/esd_mean        0.0000386
_refine_ls_shift/su_max          0.0006345
_refine_ls_structure_factor_coef F
_refine_ls_weighting_scheme
;
w = 1/[\s(F)^2^+(0.025F)^2^],
except w = 0 if I < 3\s(I)
;
_refine_ls_wR_factor_all         0.0407
_refine_ls_wR_factor_ref         0.0407
_reflns_number_gt                3220
_reflns_number_total             4470
_reflns_threshold_expression     I>=3\s(I)
_cod_data_source_file            br0099.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_cell_volume        529.39
_cod_database_code               2102185