29 May 2025
SIESTA 5.4.0 Release: Enhanced QM/MM capabilities and major performance improvements
MaX is pleased to announce the release of SIESTA 5.4.0, the second major update in the SIESTA 5 series. This version brings significant improvements in functionality, performance, and interoperability, making SIESTA more powerful and easier to use for materials science research.
SIESTA is one of the MaX Lighthouse codes. It is widely used for first-principles simulations of materials and molecules based on density functional theory. It supports a variety of tasks, including geometry optimization, molecular dynamics, electronic structure analysis, and transport properties. Its efficiency, especially for large systems, makes it an essential tool for researchers across academia and industry.
Among the key features of this latest release, we highlight the full support for QM/MM simulations. The new module includes an in-house QM/MM driver and facilitates integration with other molecular mechanics engines. Electrostatic interactions are now computed directly within SIESTA using an optimized method for faster and more scalable calculations. This makes SIESTA more versatile and attractive for multiscale modeling workflows.
Performance has also been improved with FFTW support for the Poisson solver, better parallelization over atomic matrix elements, and redesigned initialization of atomic tables. These changes enhance efficiency and reduce computational bottlenecks, especially for large systems and demanding simulations.
Other important features provided by the 5.4.0 release include the ability to calculate derivatives of Hamiltonian and overlap matrices during force constant runs, expanded options for writing Hamiltonian and density matrix files, and finer control over basis set pressure at the species level.
This release is the result of collaboration between the Institut Català de Nanociència i Nanotecnologia (ICN2), Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), and the MaX Centre of Excellence for Materials at the eXascale (MaX CoE). We thank all contributors for their ongoing commitment to advancing open-source computational tools for materials research and innovation.
Download SIESTA 5.4.0 here: SIESTA 5.4.0 Download
Visit the SIESTA webpage: SIESTA webpage
About SIESTA
SIESTA is one of the lighthouse codes supported by the MaX Centre of Excellence, dedicated to enabling exascale-level materials science research. It provides efficient and accurate DFT-based simulations and continues to evolve as a high-impact tool for the scientific community. The software is particularly relevant for users interested in multiscale modeling, high-performance computing, and method development. SIESTA is regularly optimized by a large number of developers and scientists. The added functionalities and improved performance support academic and industrial researchers in tackling complex materials science simulations with greater accuracy and speed.