Dynamic loading of matter occurs during astrophysical impacts, and also in laboratory experiments on the response of materials to extreme conditions. These properties, in particular the equation of state (EOS), are also important in understanding the structure and evolution of planets and stars. Ultimately, the EOS depends on the electronic structure of matter, but accurate predictions are not computationally tractable over wide ranges of states, needed for general-purpose models.
In the last few years, we have extended the simplified “atom-in-jellium” (AJ) electronic structure model to predict material properties of elements efficiently over unusually wide ranges. We can now predict the ionic EOS including the decrease in heat capacity from 3 to 1.5 kB per atom as ions become free, melting at high pressure, the shear modulus, and plastic flow. AJ theory is relatively inaccurate around ambient conditions but otherwise seems as valid as more rigorous approaches, even to white dwarf conditions. These studies shed light on condensed matter physics more generally, including an explanation for the empirical Lindemann melting law. Some of these developments can be extended to alloys and compounds, including minerals.