def zero_energy_format(zero_ene):
    """ Formats the zero point energy into a string that
        is appropriate for a MESS input file.

        :param zero_ene: zero point energy value
        :type zero_ene: float
        :return zero_ene_str: MESS-format string containing energy
        :rtype string
    """

    zero_ene_str = (
        'ZeroEnergy[kcal/mol]      {0:<8.2f}'.format(zero_ene)
    )

    return zero_ene_str