Application of grand-canonical ensemble Monte Carlo simulation in metals using cavity-biased method

ABSTRACT

A critic issue of the application of the conventional grand-canonical Monte Carlo (GCMC) method in high-density systems is the low acceptance ratio of insertion. Previous studies have revealed that this can be overcome by the cavity-biased (CB) insertion method in simulations of vapours, fluids and liquids. Here, we demonstrate that the method is also highly efficient in metals. Using the Fe–H system as an example, we find that the acceptance ratio of inserting H into Fe lattice is increased by several times using the CB GCMC method. The method is more valid than the conventional one at bulk H concentration over 5‰, implying that the CB GCMC method is highly efficient when there are deep traps for H in simulation systems, i.e. dislocations and interfaces. Application of the method in nanocrystalline Fe shows that the CPU time required for obtaining an equilibrium distribution of H is reduced by 60%.

KEYWORDS:

• Atomistic simulation
• Monte Carlo technique
• Cavity-biased method
• Hydrogen

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Natural Science Foundation of China: [Grant Number 51271122].