mkdir "FULL_BSE_Densities" folder (needed for bse run) in the desired folder

def make_FULL_BSE_Densities_folder(self, folder):
        """
        mkdir "FULL_BSE_Densities" folder (needed for bse run) in the desired folder
        """

        if os.path.exists(folder + "/FULL_BSE_Densities"):
            return "FULL_BSE_Densities folder already exists"
        else:
            os.makedirs(folder + "/FULL_BSE_Densities")
            return "makedirs FULL_BSE_Densities folder"