import re


def split_atom_label(label):
    """
    Split atomic label used in ref or cif formats into computer-readable parts.
    :param label: Short atomic label such as "C12A" or "Fe1".
    :type label: str
    :return: 3-element tuple with element, number, and suffix, as str.
    :rtype: tuple
    """
    label_regex = re.compile(r'(\d+|\s+)')
    label_fragments = label_regex.split(label)
    element = label_fragments[0]
    number = label_fragments[1]
    suffix = ''.join(label_fragments[2:])
    return element, number, suffix