data_global _chemical_name_mineral 'Jimthompsonite' loop_ _publ_author_name 'Veblen D R' 'Burnham C W' _journal_name_full 'American Mineralogist' _journal_volume 63 _journal_year 1978 _journal_page_first 1053 _journal_page_last 1073 _publ_section_title ; New biopyriboles from Chester, Vermont: II. The crystal chemistry of jimthompsonite, clinojimthompsonite, and chesterite, and the amphibole-mica reaction ; _database_code_amcsd 0000687 _chemical_formula_sum '(Mg3.892 Fe1.108) Si6 (O18 H2)' _cell_length_a 18.626 _cell_length_b 27.230 _cell_length_c 5.297 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 2686.564 _exptl_crystal_density_diffrn 3.041 _symmetry_space_group_name_H-M 'P b c a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,1/2+z' '-x,1/2+y,1/2-z' '1/2-x,1/2+y,z' '1/2+x,1/2-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 Mg1 0.12565 0.27883 0.89663 0.94000 0.00545 Fe1 0.12565 0.27883 0.89663 0.06000 0.00545 Mg2 0.12535 0.33533 0.39566 0.84400 0.00735 Fe2 0.12535 0.33533 0.39566 0.15600 0.00735 Mg3 0.12506 0.39257 0.89577 0.92200 0.00532 Fe3 0.12506 0.39257 0.89577 0.07800 0.00532 Mg4 0.12485 0.45165 0.39642 0.98900 0.00443 Fe4 0.12485 0.45165 0.39642 0.01100 0.00443 Fe5 0.12369 0.50609 0.89507 0.80300 0.00697 Mg5 0.12369 0.50690 0.89507 0.19700 0.00697 Si1a 0.27111 0.27787 0.55967 1.00000 0.00380 Si2a 0.26964 0.39005 0.56980 1.00000 0.00507 Si3a 0.27242 0.44700 0.06669 1.00000 0.00532 Si1b 0.48025 0.27769 0.26700 1.00000 0.00418 Si2b 0.48078 0.38929 0.27278 1.00000 0.00545 Si3b 0.47579 0.44553 0.77466 1.00000 0.00595 O-Ha 0.18329 0.33519 0.06241 1.00000 0.00621 O-Hb 0.56861 0.33513 0.76931 1.00000 0.00633 O1a 0.30061 0.24981 0.31159 1.00000 0.00823 O2a 0.18399 0.27777 0.56140 1.00000 0.00507 O3a 0.29949 0.33407 0.55638 1.00000 0.00861 O4a 0.18325 0.39170 0.56291 1.00000 0.00633 O5a 0.29980 0.41491 0.82585 1.00000 0.00925 O6a 0.30187 0.42028 0.33148 1.00000 0.00874 O7a 0.18560 0.44852 0.06801 1.00000 0.00697 O8a 0.31330 0.49841 0.08080 1.00000 0.00773 O1b 0.45141 0.24443 0.03443 1.00000 0.00684 O2b 0.56718 0.27792 0.26828 1.00000 0.00519 O3b 0.45168 0.33338 0.23045 1.00000 0.00823 O4b 0.56725 0.39207 0.27127 1.00000 0.00760 O5b 0.44881 0.42441 0.05168 1.00000 0.00747 O6b 0.45138 0.40886 0.54386 1.00000 0.00963 O7b 0.56296 0.44849 0.77718 1.00000 0.00798 O8b 0.43394 0.49561 0.71391 1.00000 0.00785