code: def run_aconvasp_command(command, structure):
      
      poscar = Poscar(structure)
      p = subprocess.Popen(command, stdout=subprocess.PIPE,
                           stdin=subprocess.PIPE,
                           stderr=subprocess.PIPE)
      output = p.communicate(input=poscar.get_string())
      return output
docs: Helper function for calling aconvasp with different arguments