  Core-level spectra of liquids can be difficult to interpret due to the
presence of a range of local environments. We present computational methods for
investigating core-level spectra based on the idea that both local structural
parameters and the X-ray spectra behave as functions of the local atomic
configuration around the absorbing site. We identify correlations between
structural parameters and spectral intensities in defined regions of interest,
using the oxygen K-edge excitation spectrum of liquid water as a test case. Our
results show that this kind of analysis can find the main structure-spectral
relationships of ice, liquid water, and supercritical water.
