data_global _chemical_name_mineral 'Rammelsbergite' loop_ _publ_author_name 'Kjekshus A' 'Rakke T' 'Andresen A' _journal_name_full 'Acta Chemica Scandinavica' _journal_volume A28 _journal_year 1974 _journal_page_first 996 _journal_page_last 1000 _publ_section_title ; Compounds of the marcasite type crystal structure. IX. Structural data for FeAs2, FeSe2, NiAs2, NiSb2, and CuSe2 ; _database_code_amcsd 0011937 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Ni As2' _cell_length_a 4.7582 _cell_length_b 5.7949 _cell_length_c 3.5440 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 97.720 _exptl_crystal_density_diffrn 7.087 _symmetry_space_group_name_H-M 'P n n m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,1/2+z' '1/2-x,1/2+y,1/2-z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-z' 'x,y,-z' '-x,-y,z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Ni 0.00000 0.00000 0.00000 As 0.20170 0.36910 0.00000