Set the solvent model to PCM. Default parameters are trying to comply to
        gaussian default value

        Args:
            pcm_params (dict): The parameters of "$pcm" section.
            solvent_key (str): for versions < 4.2 the section name is "pcm_solvent"
            solvent_params (dict): The parameters of solvent_key section
            radii_force_field (str): The force fied used to set the solute
                radii. Default to UFF.

def use_pcm(self, pcm_params=None, solvent_key="solvent", solvent_params=None,
                radii_force_field=None):
        """
        Set the solvent model to PCM. Default parameters are trying to comply to
        gaussian default value

        Args:
            pcm_params (dict): The parameters of "$pcm" section.
            solvent_key (str): for versions < 4.2 the section name is "pcm_solvent"
            solvent_params (dict): The parameters of solvent_key section
            radii_force_field (str): The force fied used to set the solute
                radii. Default to UFF.
        """
        self.params["pcm"] = dict()
        self.params[solvent_key] = dict()
        default_pcm_params = {"Theory": "SSVPE",
                              "vdwScale": 1.1,
                              "Radii": "UFF"}
        if not solvent_params:
            solvent_params = {"Dielectric": 78.3553}
        if pcm_params:
            for k, v in pcm_params.items():
                self.params["pcm"][k.lower()] = v.lower() \
                    if isinstance(v, str) else v

        for k, v in default_pcm_params.items():
            if k.lower() not in self.params["pcm"].keys():
                self.params["pcm"][k.lower()] = v.lower() \
                    if isinstance(v, str) else v
        for k, v in solvent_params.items():
            self.params[solvent_key][k.lower()] = v.lower() \
                if isinstance(v, str) else copy.deepcopy(v)
        self.params["rem"]["solvent_method"] = "pcm"
        if radii_force_field:
            self.params["pcm"]["radii"] = "bondi"
            self.params["rem"]["force_fied"] = radii_force_field.lower()