Numerical estimate for boiling points via Wang–Landau simulations

Abstract

We show how molecular simulations, based on the Wang–Landau (WL) sampling method, can be used to determine the boiling points of a wide range of fluids. The simulations presented here rely on an efficient sampling of the isothermal–isobaric ensemble. This circumvents the difficult deletion/insertion of molecules in dense liquid phases, such as those encountered at the standard boiling point. Using a combination of the WL sampling and hybrid Monte Carlo simulations, we show how we can determine the standard boiling point of atomic fluids, such as liquid metals. We then apply WL configurational bias Monte Carlo simulations to determine the boiling points for a series of long n-alkane chains (icosane, tetracosane and triacontane). The results obtained in this work are in good agreement with the available experimental data and simulation results.

Keywords:

• boiling point
• Wang–Landau sampling
• isothermal–isobaric partition function
• canonical partition function
• molecular simulation

Acknowledgement

Partial funding for this research was provided by NSF through CAREER award DMR-1052808.