def METHOD_NAME(md_base_units: Dict[str, Union[str, float]]):
    """
    Define the units used in molecular dynamics. This is done based on the base units for energy, length and mass
    from which all other quantities are derived.
    Args:
        md_base_units (dict): Dictionary defining the basic units for molecular dynamics simulations
    Returns:
        dict(str, float):
    """
    # Initialize basic unit system
    md_base_units = {u: _parse_unit(md_base_units[u]) for u in md_base_units}
    # Set up unit dictionary
    units = Units(md_base_units)
    # Derived units (MD internal -> ASE internal)
    units["time"] = units["length"] * np.sqrt(units["mass"] / units["energy"])
    units["force"] = units["energy"] / units["length"]
    units["stress"] = units["energy"] / units["length"] ** 3
    units["pressure"] = units["stress"]
    # Conversion of length units
    units["A"] = aseunits.Angstrom / units["length"]
    units["Ang"] = units["A"]
    units["Angs"] = units["A"]
    units["Angstrom"] = units["A"]
    units["nm"] = aseunits.nm / units["length"]
    units["a0"] = aseunits.Bohr / units["length"]
    units["Bohr"] = units["a0"]
    # Conversion of energy units
    units["kcal"] = aseunits.kcal / units["energy"]
    units["kJ"] = aseunits.kJ / units["energy"]
    units["eV"] = aseunits.eV / units["energy"]
    units["Hartree"] = aseunits.Hartree / units["energy"]
    units["Ha"] = units["Hartree"]
    # Time units
    units["fs"] = aseunits.fs / units["time"]
    units["s"] = aseunits.s / units["time"]
    units["aut"] = aseunits._aut * aseunits.s / units["time"]
    # Pressure units
    units["Pascal"] = aseunits.Pascal / units["pressure"]
    units["bar"] = 1e5 * units["Pascal"]
    # Mol
    units["mol"] = aseunits.mol
    # Mass
    units["Dalton"] = 1.0 / units["mass"]
    units["amu"] = aseunits._amu / units["mass"]
    # Charge distributions
    units["Debye"] = aseunits.Debye / (units["charge"] * units["length"])
    units["C"] = aseunits.C / units["charge"]
    # Constants (internal frame)
    units["kB"] = aseunits.kB / units["energy"]  # Always uses Kelvin
    units["hbar"] = (
        aseunits._hbar * (aseunits.J * aseunits.s) / (units["energy"] * units["time"])
    )  # hbar is given in J*s by ASE
    units["ke"] = (
        units["a0"] * units["Ha"] / units["charge"] ** 2
    )  # Coulomb constant is 1 in atomic units
    # For spectra
    units["hbar2icm"] = units["hbar"] * 100.0 * aseunits._c * aseunits._aut
    return units