There are selected experimental data sets, which appear reliable, which suggest
the accuracy of Chantler  compared to, e.g., Saloman, Hubbell, and
Scofield . Both theoretical approaches had
large uncertainties in the soft x-ray near-edge region for a range of elements,
for well-defined reasons. The convergence error of Chantler  was at all
times within 1.5 σ. However, this
still represented a large area of concern, particularly for present and future
experimental investigations, even though it was often more accurate than
ref. . We have improved upon the theoretical
uncertainty for f2 in these regions (to an estimated
In regions above edges, the uncertainty in f2 of this work
and that of Chantler  reduces to an estimated 1 %. This is also the
typical uncertainty quoted by other theoretical work, yet discrepancies between
these often exist at the 6 % level. Uncertainties in f1
are dominated by small errors or sharp discontinuities in f2.
Therefore, the precision of local structure in f1 remains
uncertain, as listed in Table 2. In all cases, uncertainties are quoted
as percentages of
Future experimental and theoretical work holds the prospect of addressing many of the issues raised in this work. The tabulation presented here resolves many of the difficulties encountered with previous tabulations, while some aspects remain to be treated in greater depth in the future, perhaps including aspects of collective behavior and near-edge smoothing. There also appears to be a high priority for a comprehensive recalculation of scattering factors based on the approach of this work.
For general application, the tabulation presented here should be combined with Chantler  and may make use of scattering coefficients contained in Hubbell and Øverbø  (σcoh), and Hubbell et al.  (σincoh), for example.