loop_
    _ndb_virtual_bond.atom_site_id_1
    _ndb_virtual_bond.atom_site_id_2
    _ndb_virtual_bond.model_id
    _ndb_virtual_bond.dist
    _ndb_virtual_bond.site_symmetry_1
    _ndb_virtual_bond.site_symmetry_2
      1  5 1  3.40  1_555  1_555 
    # - - - - data truncated for brevity - - - -