Boltzmann bias grand canonical Monte Carlo

TL;DR

This paper introduces an efficient grand canonical Monte Carlo method for simulating adsorption of structured particles in confined geometries, extending it to path integral simulations for hydrogen isotopes in nanotubes and slit pores.

Contribution

It develops a novel insertion technique for structured particles in confined spaces and extends it to path integral simulations, enabling accurate modeling of adsorption phenomena.

Findings

The new method improves efficiency over standard algorithms.

It accurately predicts hydrogen isotope adsorption in nanotubes and slit pores.

The approach is applicable to oligomers and polymers in narrow channels.

Abstract

We derive an efficient method for the insertion of structured particles in grand canonical Monte Carlo simulations of adsorption in very confining geometries. We extend this method to path integral simulations and use it to calculate the isotherm of adsorption of hydrogen isotopes in narrow carbon nanotubes (2D confinement) and slit pores (1D confinement) at the temperatures of 20 K and 77 K, discussing its efficiency by comparison to the standard path integral grand canonical Monte Carlo algorithm. We use this algorithm to perform multicomponent simulations in order to calculate the hydrogen isotope selectivity for adsorption in narrow carbon nanotubes and slit pores at finite pressures. The algorithm described here can be applied to the study of adsorption of real oligomers and polymers in narrow pores and channels.