FreeBird.jl: An Extensible Toolbox for Simulating Interfacial Phase Equilibria

TL;DR

FreeBird.jl is a flexible, Julia-based toolkit that enables detailed computational studies of phase equilibria at interfaces across various system types and configurations, supporting multiple sampling algorithms.

Contribution

It introduces an extensible, modular platform that unifies atomistic and lattice models for interfacial phase equilibrium simulations using Julia's advanced features.

Findings

Supports diverse system configurations and models.

Incorporates multiple sampling algorithms.

Offers a flexible, modular, and high-performance framework.

Abstract

We present FreeBird, an extensible Julia-based platform for computational studies of phase equilibria at generic interfaces. The package supports a range of system configurations, from atomistic solid surfaces to coarse-grained lattice$-$gas models, with energies evaluated using classical interatomic potentials or lattice Hamiltonians. Both atomistic and lattice systems accommodate single- or multi-component mixtures with flexibly definable surface and lattice geometries. Implemented sampling algorithms include nested sampling, Wang$-$Landau sampling, Metropolis Monte Carlo, and, for tractable lattice systems, exact enumeration. Leveraging Julia's type hierarchies and multiple dispatch, FreeBird provides a modular interface that allows seamless integration of system definitions, energy evaluators, and sampling schemes. Designed for flexibility, extensibility, and performance, FreeBird offers a versatile framework for exploring the thermodynamics of interfacial phenomena.