JuCLS database of core-level shifts from all-electron density functional theory simulations for chemical analysis of X-ray photoelectron spectra

We present the JuCLS (Jülich core-level shifts) database which collects first principles calculations of core-level binding energies and core-level shifts (also known as chemical shifts). The calculations for this database were performed with the FLEUR program [1], a feature-full, freely available, open source FLAPW (full-potential linearized augmented planewave) code, based on density-functional theory. The FLAPW-method is a very accurate all-electron method which within density functional theory is universally applicable to all atoms of the periodic table. All calculations are run with AiiDA through workflows within the AiiDA-FLEUR package (version 0.12.3) [2]. Our database collects predicted core-level shifts, binding energies for X-ray photoelectron spectroscopy (XPS) and as a side product formation energies. Core-level shifts are calculated within the initial state approximation and binding energies are extracted from core-hole simulations. The JuCLS v1.0 contains initial state core-level shifts and formation energies on 4435 of the 5058 stable binary metals from the Materials project database (MP) and calculations on 1271 elemental crystals from the Inorganic Crystal Structure Database (ICSD). This corresponds currently to over 130 000 unique core-level shifts and over 15 000 unique main line core-level shifts. The JuCLS database allows for the construction of theoretical X-ray photoelectron spectra containing a possible mixture of these materials. Furthermore, it allows for a direct chemical characterization of materials. [1] https://flapw.de and www.judft.de [2] https://github.com/JuDFTteam/aiida-fleur