W-SLDA Toolkit: A simulation platform for ultracold Fermi gases

Abstract

We present the W-SLDA Toolkit, a general-purpose software package for simulating ultracold Fermi gases within the framework of density functional theory and its time-dependent extensions. The toolkit enables fully microscopic studies of interacting superfluid systems across the BCS-BEC crossover, including spin-imbalanced configurations and arbitrary external geometries. It provides both static and time-dependent solvers capable of describing a broad range of phenomena in one-, two-, and three-dimensional settings. In addition, the toolkit incorporates functionality for solving the standard Bogoliubov-de Gennes equations for fermions, extending its applicability to other physical systems such as superconductors. The code is implemented in C with GPU acceleration and is optimized for hybrid CPU/GPU execution on modern high-performance computing platforms. It ensures scalability on leadership-class supercomputers, enabling fully three-dimensional simulations with large atomic numbers, and allows for direct benchmarks of ultracold-atom experimental setups. Its modular architecture facilitates straightforward extensions, user customization, and seamless interoperability with other scientific software frameworks. Furthermore, an extensive collection of practical usage examples is provided through the integrated reproducibility packs functionality, ensuring transparency and reproducibility of computational results.