The state of warm dense matter (WDM) is usually defined from the perspective of the free carriers in the system: the electrons are partially to highly degenerate and (at least) the ions feel strong interactions. Strong electron-ion interactions also lead to the creation of bound states that are, however, strongly modified by the medium around. The talk will give an overview of simulations and other theoretical approaches to WDM with the focus on effects due to bound electrons. Comparisons with experiments using x-ray scattering will be made and recent advances discussed. A final outlook will address open questions remaining.
