def get_macro_mol_sel(pdb_processed_file,selection='protein or dna or rna'):
  """
  Get macro molecule selection from a PBD interpretation object, for non bonded
  overlaps calculation

  Args:
    pdb_processed_file : Object result from pdb_interpretation of a file
    selection (str): By default a string to select the macro molecule.

  Return:
    macro_mol_sel (flex.bool): selection array
  """
  proxies = pdb_processed_file.all_chain_proxies
  cache = proxies.pdb_hierarchy.atom_selection_cache()
  macro_mol_sel = proxies.selection(
    cache=cache,
    string=selection )
  return macro_mol_sel