data_1008990
_chemical_name_systematic          'Neptunium arsenide (1/2)'
_chemical_formula_structural       'Np As2'
_chemical_formula_sum              'As2 Np'
_publ_section_title
;
Np As2: Magnetic form factors and tentative crystal field model
;
loop_
_publ_author_name
  'Delapalme, A'
  'Mulak, J'
  'Blaise, A'
  'Fournier, J M'
_journal_name_full                 'Journal of Magnetism and Magnetic Materials'
_journal_coden_ASTM                JMMMDC
_journal_volume                    30
_journal_year                      1982
_journal_page_first                117
_journal_page_last                 121
_cell_length_a                     3.930(5)
_cell_length_b                     3.93
_cell_length_c                     8.137(5)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       125.7
_cell_formula_units_Z              2
_symmetry_space_group_name_H-M     'P 4/n m m S'
_symmetry_Int_Tables_number        129
_symmetry_cell_setting             tetragonal
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,-y,z'
  '1/2+x,1/2+y,-z'
  '1/2-x,1/2-y,-z'
  '-x,y,z'
  'x,-y,z'
  '1/2-x,1/2+y,-z'
  '1/2+x,1/2-y,-z'
  '-y,x,-z'
  'y,-x,-z'
  '1/2-y,1/2+x,z'
  '1/2+y,1/2-x,z'
  'y,x,-z'
  '-y,-x,-z'
  '1/2+y,1/2+x,z'
  '1/2-y,1/2-x,z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Np0    0.000
  As0    0.000
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  Np1   Np0    2 c 0. 0.5 0.281 1.  0 d
  As1   As0    2 a 0. 0. 0. 1.  0 d
  As2   As0    2 c 0. 0.5 0.639 1.  0 d