data_global _chemical_name_mineral 'Omphacite' loop_ _publ_author_name 'Pavese A' 'Bocchio R' 'Ivaldi G' _journal_name_full 'Mineralogical Magazine' _journal_volume 64 _journal_year 2000 _journal_page_first 983 _journal_page_last 993 _publ_section_title ; In situ high temperature single crystal X-ray diffraction study of a natural omphacite Note: structure at room temperature (T=298K) ; _database_code_amcsd 0014547 _chemical_compound_source 'Gorduno, Lepontine Alps, Switzerland' _chemical_formula_sum '(Ca.5 Na.5) Mg.46 Al.51 Fe.06 Si1.97 O6' _cell_length_a 9.569 _cell_length_b 8.759 _cell_length_c 5.256 _cell_angle_alpha 90 _cell_angle_beta 106.96 _cell_angle_gamma 90 _cell_volume 421.372 _exptl_crystal_density_diffrn 3.328 _symmetry_space_group_name_H-M 'P 1 2/n 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-x,y,1/2-z' '1/2+x,-y,1/2+z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv CaM2 0.75000 0.05230 0.25000 0.29100 0.00940 NaM2 0.75000 0.05230 0.25000 0.70900 0.00940 CaM21 0.75000 0.45050 0.75000 0.70900 0.01050 NaM21 0.75000 0.45050 0.75000 0.29100 0.01050 MgM1 0.75000 0.65926 0.25000 0.46000 0.00690 AlM1 0.75000 0.65926 0.25000 0.48000 0.00690 FeM1 0.75000 0.65926 0.25000 0.06000 0.00690 MgM11 0.75000 0.84740 0.75000 0.46000 0.00330 AlM11 0.75000 0.84740 0.75000 0.48000 0.00330 FeM11 0.75000 0.84740 0.75000 0.06000 0.00330 SiT1 0.03948 0.84770 0.22674 0.98500 0.00440 AlT1 0.03948 0.84770 0.22674 0.01500 0.00440 SiT2 0.03722 0.66247 0.73047 0.98500 0.00430 AlT2 0.03722 0.66247 0.73047 0.01500 0.00430 O11 0.86300 0.83930 0.12010 1.00000 0.00670 O12 0.86100 0.67800 0.64820 1.00000 0.00670 O21 0.11490 0.01020 0.30930 1.00000 0.00790 O22 0.10610 0.49750 0.80500 1.00000 0.00900 O31 0.10660 0.76650 0.00390 1.00000 0.00670 O32 0.09800 0.74030 0.49770 1.00000 0.00710