code: def write_to_file(self, f, file_unit=angstrom):
          
          xyz_writer = XYZWriter(f, self.symbols, file_unit=file_unit)
          for title, coordinates in zip(self.titles, self.geometries):
              xyz_writer.dump(title, coordinates)
docs: Write the trajectory to a file
  
             Argument:
              | ``f``  -- a filename or a file-like object to write to
  
             Optional argument:
              | ``file_unit``  --  the unit of the values written to file
                                   [default=angstrom]