Atomic-level breakdown of Green–Kubo relations provides new insight into the mechanisms of thermal conduction

Precise control of thermophysical properties of liquids through tailor-made design of the liquid molecular structure is a goal that, if achieved, could have significant positive impacts on machine design, performance and durability. In this work we show how the breakdown of the Green–Kubo relations down to the atomic level in molecular dynamics simulation can give useful insight into the mechanisms of thermal conduction. Using a group of five small alcohols as a case study, we demonstrate how combining this level of insight with differential-structure analysis reveals the competition for conduction between carbon and hydroxyl group atoms, and show how this competition contributes to the change in thermal conductivity observed in experiment. We hope that this method will become a useful tool in the quest for molecular-structure based thermal design.