Returns the zero point energy from a list of frequencies.

    Parameters
    ----------
    viblist : List of numbers or string of list of numbers.

    Returns
    -------
    ZPE : Zero point energy in eV.

def get_ZPE(viblist):
    """Returns the zero point energy from a list of frequencies.

    Parameters
    ----------
    viblist : List of numbers or string of list of numbers.

    Returns
    -------
    ZPE : Zero point energy in eV.
    """
    if type(viblist) is str:
        l = ast.literal_eval(viblist)
    else:
        l = viblist
    l = [float(w) for w in l]
    ZPE = 0.5*sum(l)*cm2ev
    return(ZPE)