def generic_qpt_labels():
    """
    Returns a dictionary relating fractional q-point label strings to their
    coordinates e.g. '1/4 1/2 1/4' = [0.25, 0.5, 0.25]. Used for labelling
    q-points when the space group can't be calculated
    """
    label_strings = ['0', '1/4', '3/4', '1/2', '1/3', '2/3', '3/8', '5/8']
    label_coords = [0.0, 0.25, 0.75, 0.5, 1.0 / 3.0, 2.0 / 3.0, 0.375, 0.625]
    generic_labels = {}
    for i, s1 in enumerate(label_strings):
        for j, s2 in enumerate(label_strings):
            for k, s3 in enumerate(label_strings):
                key = s1 + ' ' + s2 + ' ' + s3
                value = [label_coords[i], label_coords[j], label_coords[k]]
                generic_labels[key] = value
    return generic_labels
