def _fancy_to_raw(sheng):
    """
    Converts force constants namedtuple format defined above (_ShengEntry) to
    format used for writing shengBTE files.
    """
    raw_sheng = []
    for entry in sheng:
        raw_entry = list(entry[:6])
        raw_entry[0] += 1
        raw_entry[1] += 1
        raw_entry[2] += 1
        raw_sheng.append(raw_entry)
    return raw_sheng
