Project title: Effects of electronic temperature on the forces between atoms
Supervisors: Matthew Foulkes and Derek Lee
Currently, there are well established methods for describing cold dense systems through condensed matter physics. Likewise, for hot diffuse systems plasma physics techniques are often used. However, for the "bridge" between the two, the so-called warm dense matter (WDM) regime, both sets of tools fail to describe systems accurately. One promising method is thermal density functional theory. Recently, finite temperature XC functionals (those that include electronic temperature effects) have been developed, and so I am looking at how the forces between atoms in the WDM regime are affected by these finite temperature effects, and more generally where the finite temperature effects are most important.
I am also looking at empirical force-fields and whether one that incorporates electronic temperature effects can be developed, or whether a current zero temperature force-field, such as the Finnis-Sinclair potential, could be adapted to account for temperature effects. This is of interest primarily for simulation needs, as molecular dynamics calculations are costly and slow, but also because empirically derived force-fields can give some insight into both where effects originate from and how they can be expected to change under different conditions or in different structures.