def _name_key(name_dict):
    """Reconstruct name for dictionary key used in Equilibrium compute methods.

    Parameters
    ----------
    name_dict : dict
        name dictionary created by format_name method

    Returns
    -------
    name_key : str

    """
    out = name_dict["base"]
    if name_dict["sups"] != "":
        out += "^" + name_dict["sups"]
    if name_dict["subs"] != "":
        out += "_" + name_dict["subs"]
    if name_dict["d"] != "":
        out += "_" + name_dict["d"]
    return out