code: def save_scan_plot(self, filename="scan.pdf",
                         img_format="pdf", coords=None):
          
          plt = self.get_scan_plot(coords)
          plt.savefig(filename, format=img_format)
docs: Save matplotlib plot of the potential energy surface to a file.
  
          Args:
              filename: Filename to write to.
              img_format: Image format to use. Defaults to EPS.
              coords: internal coordinate name to use as abcissa.