Abstract: | At the molecular level there are atoms and forces, whereas continuum theories deal with fields and stress. To connect between these models of reality it is necessary to obtain expressions for continuum variables, such as stress and heat flux, at the molecular level. To date, many different expressions have been proposed and some confusion exists in the literature as to which is "correct". We show that a unified framework, based on the work of Irving and Kirkwood and later Noll, can be established from which all other expressions can be derived. Interestingly, it turns out that subtle arguments related to the nature of interatomic potentials play an important role in the derivation. The theoretical framework as well as numerical results will be presented.
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