$\texttt{express}$: extensible, high-level workflows for swifter $\textit{ab initio}$ materials modeling

Abstract: In this work, we introduce an open-source $\texttt{Julia}$ project, $\texttt{express}$, an extensible, high-throughput, high-level workflow framework that aims to automate $\textit{ab initio}$ calculations for the materials science community. $\texttt{Express}$ is shipped with well-tested workflow templates, including structure optimization, equation of state (EOS) fitting, phonon spectrum (lattice dynamics) calculation, and thermodynamic property calculation in the framework of the quasi-harmonic approximation (QHA). It is designed to be highly modularized so that its components can be reused across various occasions, and customized workflows can be built on top of that. Users can also track the status of workflows in real-time, and rerun failed jobs thanks to the data lineage feature $\texttt{express}$ provides. Two working examples, i.e., all workflows applied to lime and akimotoite, are also presented in the code and this paper.