Electronic Structure Modules

ELSIELectronic Structure Infrastructure provides and enhances scalable, open-source software library solutions for electronic structure calculations in materials science, condensed matter physics, chemistry, molecular biochemistry, and many other fields. ELSI focuses on methods that solve or circumvent eigenvalue problems in electronic structure theory. The ELSI infrastructure should also be useful for other challenging eigenvalue problems.

ELSI deals with the Kohn–Sham eigenvalue problem, which is central to Kohn–Sham density-functional theory, one of the most widely used methods in electronic structure. This problem is often the bottleneck in large scale calculations by high-performance computation and many different algorithms and strategies exist to tackle it. ELSI acts as a unified software interface to access different algorithms and their corresponding implementations. This greatly simplifies the implementation and optimal use of the different strategies.



SIRIUS is a domain specific library for electronic structure calculations. It implements pseudopotential plane wave (PP-PW) and full potential linearized augmented plane wave (FP-LAPW) methods and is designed for GPU acceleration of popular community codes such as Exciting, Elk and Quantum ESPRESSO. SIRIUS is used in production at CSCS to enable QE on GPUs. The library is open-source (BSD 2-clause licence) and is freely available. SIRIUS is written in C++11 with MPI, OpenMP and CUDA/ROCm programming models. SIRIUS is organised as a collection of classes that abstract away the different building blocks of DFT self-consistency cycle.

CoE: MaX


BigDFT is an electronic structure pseudopotential code that employs Daubechies wavelets as a computational basis, designed for usage on massively parallel architectures. It features high-precision cubic-scaling DFT functionalities enabling treatment of molecular, slab-like as well as extended systems, and efficiently supports hardware accelerators such as GPUs since 2009.

CoE: MaX


FLEUR (Full-potential Linearised augmented plane wave in EURope) is a code family for calculating groundstate as well as excited-state properties of solids within the context of density functional theory (DFT). A key difference with respect to the other MAX-codes and indeed most other DFT codes lies in the treatment of all electrons on the same footing. Thereby we can also calculate the core states and investigate effects in which these states change. FLEUR is based on the full-potential linearised augmented plane wave method, a well established scheme often considered to provide the most accurate DFT results and used as a reference for other methods. The FLEUR family consists of several codes and modules: a versatile DFT code for the ground-state properties of multicomponent magnetic one-, two- and three-dimensional solids. A focus of the code is on non-collinear magnetism, determination of exchange parameters, spin-orbit related properties (topological and Chern insulators, Rashba and Dresselhaus effect, magnetic anisotropies, Dzyaloshinskii-Moriya interaction). The SPEX code implements many-body perturbation theory (MBPT) for the calculation of the electronic excitation properties of solids. It includes different levels of GW approaches to calculate the electronic self-energy including a relativistic quasiparticle self-consistent GW approach. The experimental KKRnano code, designed for highest parallel scaling, provides the possibility to utilize current supercomputers to their full extend and is applicable to dense-packed crystals.

CoE: MaX


Yambo is an open-source code that implements Many-Body Perturbation Theory (MBPT) methods (such as GW and BSE), which allows for accurate prediction of fundamental properties as band gaps of semiconductors, band alignments, defect quasi-particle energies, optics and out-of-equilibrium properties of materials, including nano-structured systems.

CoE: MaX


SIESTA (Spanish Initiative for Electronic Simulations with Thousands of Atoms) is an original method and its computer program implementation, to perform efficient electronic structure calculations and ab initio molecular dynamics simulations of molecules and solids. SIESTA’s efficiency stems from the use of strictly localized basis sets and from the implementation of linear-scaling algorithms which can be applied to suitable systems. A very important feature of the code is that its accuracy and cost can be tuned in a wide range, from quick exploratory calculations to highly accurate simulations matching the quality of other approaches, such as plane-wave and all-electron methods. SIESTA’s backronym is Spanish Initiative for Electronic Simulations with Thousands of Atoms. Since 13 May 2016, with the 4.0 version announcement, SIESTA is released under the terms of the GPL open-source license. Source packages and access to the development versions can be obtained from the DevOps platform on GitLab.

CoE: MaX


Quantum ESPRESSO is an integrated suite of Open-Source computer codes for electronic-structure calculations and materials modeling at the nanoscale. It is based on density-functional theory, plane waves, and pseudopotentials. It is a suite for first-principles electronic-structure calculations and materials modeling, distributed for free and as free software under the GNU General Public License. It is based on density-functional theory, plane wave basis sets, and pseudopotentials (both norm-conserving and ultrasoft). ESPRESSO is an acronym for opEn-Source Package for Research in Electronic Structure, Simulation, and Optimization.

The core plane wave DFT functions of QE are provided by the PWscf component, PWscf previously existed as an independent project. PWscf (Plane-Wave Self-Consistent Field) is a set of programs for electronic structure calculations within density functional theory and density functional perturbation theory, using plane wave basis sets and pseudopotentials. The software is released under the GNU General Public License.
The latest version QE-6.6 was released on 5 Aug 2020.

CoE: MaX