Compular calculates the thermal conductivity of molten salts directly from molecular simulation, a property that is notoriously difficult and expensive to measure in a 1000 °C corrosive liquid. Values reported for the same salt differ between laboratories by a factor of two to three, so the experimental baseline is itself uncertain, and the space of useful mixtures is far too large to measure exhaustively.

Across the three pure salts LiF, LiCl and KCl, our predictions match the recommended laboratory values to within about 7 % on average over the temperature range where measurements exist.

The same workflow runs unchanged on multicomponent mixtures: for the MgCl2–KCl–NaCl (40/30/30 mol %) ternary that next-generation concentrated solar power plant storage is built around, the predictions land within about 12 % of the recommended experimental range. Both results sit comfortably inside the two- to threefold disagreement between laboratories, which means simulation is no longer the limiting source of uncertainty for this property. Heat capacity, which converges faster still, agrees to 3.7 % across all four systems and to 6 % for the ternary. Every value comes from the same force field and the same trajectories, so the panel is consistent by construction.

Getting there depends on one analysis decision. The textbook Green–Kubo estimator returns the total thermal conductivity, which in an ionic melt also counts heat carried bodily by ions as they diffuse. What an experiment actually measures is the intrinsic thermal conductivity λ, which projects that contribution out. For mass-symmetric KCl the two differ by 9 % and the shortcut looks fine; for LiF the total overshoots by 3.7 times and for LiCl by 7.5 times. We report the intrinsic λ throughout, with replica statistics behind every value, and that is why the agreement above holds across all four systems. The result is high-quality thermophysical data, quickly and cost-effectively, for R&D teams who need results they can design around.

If you have a molten-salt mixture to explore across composition and temperature, and you need the full property panel, contact us. We will run the simulations with automated workflows and deliver the results on the Compular Lab platform.

Read more in our whitepaper: compulartech.com/whitepaper/thermophysical-properties-molten-salts