data_global _chemical_name_mineral 'Coccinite' loop_ _publ_author_name 'Schwarzenbach D' 'Birkedal H' 'Hostettler M' 'Fischer P' _journal_name_full 'Acta Crystallographica, Section B' _journal_volume 63 _journal_year 2007 _journal_page_first 828 _journal_page_last 835 _publ_section_title ; Neutron diffraction investigation of the temperature dependence of crystal structure and thermal motions of red HgI2 Note: T = 30 K, powder neutron data ; _database_code_amcsd 0019548 _chemical_compound_source 'synthetic, Fluka 83379' _chemical_formula_sum 'Hg I2' _cell_length_a 4.358 _cell_length_b 4.358 _cell_length_c 12.306 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 233.718 _exptl_crystal_density_diffrn 6.457 _symmetry_space_group_name_H-M 'P 42/n m c' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-y,1/2-x,1/2+z' '1/2+y,1/2+x,1/2-z' '1/2+y,-x,1/2-z' '1/2-y,x,1/2+z' 'x,1/2-y,z' '-x,1/2+y,-z' '1/2+x,1/2+y,-z' '1/2-x,1/2-y,z' 'y,x,1/2+z' '-y,-x,1/2-z' '-y,1/2+x,1/2-z' 'y,1/2-x,1/2+z' '1/2-x,y,z' '1/2+x,-y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Hg 0.25000 0.75000 0.25000 0.00350 I 0.25000 0.25000 0.39140 0.00270 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Hg 0.00360 0.00360 0.00320 0.00000 0.00000 0.00000 I 0.00480 0.00090 0.00250 0.00000 0.00000 0.00000