exciting is an all-electron full-potential package for first-principles electronic-structure calculations, implementing different variants of the linearized augmented planewave + local orbital (LAPW+lo) method. LAPW+lo is known as the most precise numerical scheme to solve the Kohn-Sham equations of density-functional theory (DFT), reaching extremely high - up to μHartree - precision. It comes with semi-local exchange-correlation functionals as well as hybrid functionals (PBE0, HSE). Besides, it is linked to Libxc for using the numerous functionals of this library.
Lattice vibrations can be computed either with supercells or with density-functional perturbation theory (DFPT), our most recent feature to compute phonon spectra and electron-phonon coupling coefficients.
As suggested by its name, exciting has a major focus on excited-state properties. It includes a module for time-dependent DFT (TDDFT) in the linear-response regime, with a number of exchange-correlation kernels as well as a real-time implementation (RT-TDDFT). The latter can also be used together with Ehrenest dynamics. TDDFT is preferably adopted to compute absorption and electron-loss spectra of materials with weak electron-hole interaction, such as small molecules and metals, also at finite momentum transfer.
For systems with more pronounced electron-electron and/or electron-hole interaction, exciting offers a rich spectroscopy module based on many-body perturbation theory. Quasi-particle (QP) band structures can be computed in the G0W0 approximation. The QP self-consistent GW approach has been implemented and will be released soon.
The solution of the Bethe-Salpeter equation (BSE) offers an accurate description of absorption spectra in the valence and the core region on the same footing. A recent development allows for computing resonant inelastic x-ray (RIXS) spectra. Specific modules of exciting are dedicated to advanced light-matter interaction processes, such as Raman scattering, second-harmonic generation, and the magneto-optic Kerr effect.
exciting is an open-source, GPL-licensed code, with a modern source-code management, a dynamical build system, and automated tests. We offer numerous tutorials, illustrating basic and advanced features. The interface with pre- and post-processing tools integrates the capabilities of exciting for specific tasks, such as calculating elastic constants and optical coefficients. The cluster expansion code CELL can be used to deal with materials with large parent cells and thermodynamic properties.
Read more about the current developments or explore selected publications.
exciting is supported by NOMAD. If you would like to upload your data or learn more about FAIR (Findable, Accessible, Interoperalbe, Reuseable) data, visit the NOMAD webpage.
Contact us if you want to contribute code or tools or join the developers team!