# Relative Resolution: A Hybrid Formalism for Fluid Mixtures

## TL;DR

This paper introduces a hybrid formalism for fluid mixtures that combines detailed and simplified molecular models based on their relative separation, enabling accurate analysis of multi-component fluids.

## Contribution

It presents an analytical relation connecting fine-grained and coarse-grained models, facilitating hybrid modeling of fluid mixtures based on molecular proximity.

## Key findings

- Effective modeling of multi-phase fluids across state space
- Analytical expression relating detailed and simplified models
- Capable of capturing structural and thermal behaviors

## Abstract

We show here that molecular resolution is inherently hybrid in terms of relative separation: If molecules are close to each other, they must be characterized by a fine-grained (geometrically detailed) model, yet if molecules are far from each other, they may be described by a coarse-grained (isotropically simplified) model. We notably present an analytical expression for relating the two models by energy conservation. This hybrid framework is correspondingly capable of retrieving the structural and thermal behavior of various multi-component and multi-phase fluids across state space.