“…More generally, it can be inferred from the work of Kato (51) that there is no suitable method for sorting wavefunctions, such as the angular dependency H(, ) of every transition can be described as a differentiable function. Therefore, the simple ascending order sorting is generally preferred, although it fails in some special cases which can be classified as two types: (i) "Looping" transitions (18,46): There may exist {, } directions where two levels n and nЈ behave in such a way that 0 Ͻ ͉E n Ϫ E nЈ ͉ Ͻ h in a particular H interval and ͉E n Ϫ E nЈ ͉ Ն h outside of this interval. In that case, one transition appears at each extremity of the interval, and these two transitions are indexed as nnЈ p and nnЈ pϩ1 in our algorithm.…”