Niskanen, J.; Fondell, M.; Sahle, C.J.; Eckert, S.; Jay, R.; Gilmore, K.; Pietzsch, A.; Dantz, M.; Lu, X.; McNally, D.E.; Schmitt, T.; Vaz da Cruz, V.; Kimberg, V.; Gel'mukhanov, F.; Foehlisch, A.: Reply: Why X-ray spectral features are compatible to continuous distribution models in ambient water. Proceedings of the National Academy of Sciences of the United States of America 116 (2019), p. 17159
Open Accesn Version
Ambient water properties have been shown to require heterogeneity”(1) is the imperative followed by Pettersson et al.(2) to relate X-ray spectroscopic findings to a heterogeneous or 2-phase model of ambient water. In ref. 3 we question this hypothesis based on quantitative X-ray spectroscopic evidence. We come to conclude that X-ray spectroscopies support no observations related to heterogeneous, distinct structural motives in ambient water. The critique of sum rules by Pettersson et al.(2) is unjustified: Through normalization to the asymptotic behavior we avoid sum rule normalization of X-ray absorption spectroscopy (XAS). In liquid water, extended X-ray absorption fine structure oscillations are less than a percent for the used normalization range (4)(digitized), and less than twice that for ice (5). Pettersson et al.(2) point toward well-known discrepancies between XAS calculations and experiments.