  Given the unique optical properties of LiF, it is often used as an
observation window in high-temperature and pressure experiments; and, hence,
estimates of its transmission properties are necessary to interpret
observations. Since direct measurements of the thermal conductivity of LiF at
the appropriate conditions are difficult, we resort to molecular simulation
methods. Using the Belonoshko et al. (2000) empirical potential validated
against ab initio phonon density of states, we estimate the thermal
conductivity of LiF at high temperatures (1000-4000K) and pressures (100-400
GPa) with the Green-Kubo method. We also compare these estimates to those
derived directly from ab initio data. To ascertain the correct phase of LiF at
these extreme conditions we calculate the (relative) phase stability of the B1
and B2 structures using a quasiharmonic ab initio model of the free energy. We
also estimate the thermal conductivity of LiF in an uniaxial loading state that
emulates initial stages of compression in high-stress ramp loading experiments
and show the degree of anisotropy induced in the conductivity due to
deformation.
