  The first non-empirical computation of lattice thermal conductivity has been
performed for MgO using molecular dynamics (MD), a non-empirical ionic model
(the Variationally Induced Breathing (VIB) model), and Green-Kubo theory. The
computation is first-principles in the sense that no parameters are fit to
experiment. Results are presented at low pressure as a function of temperature,
and for 2500K for pressures to 290 GPa. We find an unexpectedly small pressure
effect at small compressions, perhaps due to saturation of thermal conductivity
at the high temperatures due to the small mean free path. At higher pressure
expected behavior is found.
