Do the repulsive and attractive pair forces play separate roles for the physics of liquids?

TL;DR

This paper challenges the traditional view by showing that liquids can have similar structure and dynamics despite differences in the significance of attractive forces, emphasizing the importance of total force over individual pair forces.

Contribution

It introduces a continuous series of pair potentials demonstrating that structure and dynamics are similar regardless of the prominence of attractive forces, questioning the separate roles assigned to pair forces.

Findings

Structure and dynamics are similar across different pair potentials.

Attractive forces are not always critical for liquid behavior.

Total force determines particle motion more than individual pair forces.

Abstract

According to standard liquid-state theory repulsive and attractive pair forces play distinct roles for the physics of liquids. This paradigm is put into perspective here by demonstrating a continuous series of pair potentials that have virtually the same structure and dynamics, although only some of them have attractive forces of significance. Our findings reflect the fact that the motion of a given particle is determined by the total force on it, whereas the quantity usually discussed in liquid-state theory is the individual pair force.