def METHOD_NAME(parameters: Dict[str, Any], custom_smd: Optional[str] = None) -> str:
    """
    Returns the solvent used for this calculation.
    Args:
        parameters: Dict of Q-Chem input parameters
        custom_smd: (Optional) string representing SMD parameters for a
        non-standard solvent
    """
    lot = level_of_theory(parameters)
    solvation = lot.value.split("/")[-1]
    if solvation == "PCM":
        dielectric = float(parameters.get("solvent", {}).get("dielectric", 78.39))
        dielectric_string = f"{dielectric:.2f}".replace(".", ",")
        return f"DIELECTRIC={dielectric_string}"
    # TODO: Add this once added into pymatgen and atomate
    # elif solvation == "ISOSVP":
    #     dielectric = float(parameters.get("svp", {}).get("dielst", 78.39))
    #     rho = float(parameters.get("svp", {}).get("rhoiso", 0.001))
    #     return f"DIELECTRIC={round(dielectric, 2)},RHO={round(rho, 4)}"
    # elif solvation == "CMIRS":
    #     dielectric = float(parameters.get("svp", {}).get("dielst", 78.39))
    #     rho = float(parameters.get("svp", {}).get("rhoiso", 0.001))
    #     a = parameters.get("pcm_nonels", {}).get("a")
    #     b = parameters.get("pcm_nonels", {}).get("b")
    #     c = parameters.get("pcm_nonels", {}).get("c")
    #     d = parameters.get("pcm_nonels", {}).get("d")
    #     solvrho = parameters.get("pcm_nonels", {}).get("solvrho")
    #     gamma = parameters.get("pcm_nonels", {}).get("gamma")
    #
    #     string = f"DIELECTRIC={round(dielectric, 2)},RHO={round(rho, 4)}"
    #     for name, (piece, digits) in {"A": (a, 6), "B": (b, 6), "C": (c, 1), "D": (d, 3),
    #                                   "SOLVRHO": (solvrho, 2), "GAMMA": (gamma, 1)}.items():
    #         if piece is None:
    #             piecestring = "NONE"
    #         else:
    #             piecestring = f"{name}={round(float(piece), digits)}"
    #         string += "," + piecestring
    #     return string
    elif solvation == "SMD":
        METHOD_NAME = parameters.get("smx", {}).get("solvent", "water")
        if METHOD_NAME == "other":
            if custom_smd is None:
                raise ValueError(
                    "SMD calculation with solvent=other requires custom_smd!"
                )
            names = ["DIELECTRIC", "N", "ALPHA", "BETA", "GAMMA", "PHI", "PSI"]
            numbers = [float(x) for x in custom_smd.split(",")]
            string = ""
            for name, number in zip(names, numbers):
                string += f"{name}={number:.3f};"
            return string.rstrip(",").rstrip(";").replace(".", ",")
        else:
            return f"SOLVENT={METHOD_NAME.upper()}"
    else:
        return "NONE"