A Structure-Based Framework for Fluids: From Microscopic Interactions to Criticality and Transport

In this article, we introduce a viewpoint based on structural correlations described by the pair distribution function, yielding an effective interaction coefficient that influences the critical response and conveys interacting-particle potentials to the critical and transport properties. We use ab initio model data and fit it with a Lennard-Jones (L-J) potential with Gaussian corrections. We evaluate seven ab initio-based models (CCSD(T), Dunning basis sets) for neon and argon to assess basis-set sensitivity. According to the CCSD(T) models, the critical temperature is estimated to be between 31.8 K and 55.1 K for neon and between 124.8 K and 179.7 K for argon. Molecular dynamics simulations describe argon, while neon is not fully described because quantum effects are neglected in these calculations.