Critical temperature determination on a square-well fluid using an adaptation of the microcanonical-ensemble computer simulation method

Abstract

In this work we present a novel method to evaluate the liquid–vapour critical temperature using a generalisation of the Microcanonical-ensemble computer simulation method. The isotherms of the chemical potential vs. densities are obtained for a square-well fluid with interaction range $\lambda /\sigma =1.5$: From these curves we extracted the critical temperature for different system sizes observing the change of the slope on the curves of the chemical potential in the critical region as function of the temperature. Working with different systems sizes and Finite Size Scaling Theory the critical temperature $T_c=1.2180\left(29\right)$ and the critical exponent $\nu =0.65\left(3\right)$ are obtained, without previous knowledge of $T_c$ or ν. These results are in good agreement with the reported values for this system.

GRAPHICAL ABSTRACT

Keywords:

• Theory of liquids
• square-well fluid
• numerical simulations
• critical points

PACS numbers:

• 05.10.-a
• 05.20.Jj
• 51.30.+i

Acknowledgments

The author thanks Ana Laura Benavides and Alejandro Gil-Villegas for useful comments and for the critical reading of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

This research was supported by Universidad de Guanajuato (México) under Proyecto DAIP 879/2016.