Exploring cesium–tellurium phase space via high-throughput calculations beyond semi-local density-functional theory

Abstract

Boosted by the relentless increase in available computational resources, high-throughput calculations based on first-principles methods have become a powerful tool to screen a huge range of materials. The backbone of these studies is well-structured and reproducible workflows efficiently returning the desired properties given chemical compositions and atomic arrangements as sole input. Herein, we present a new workflow designed to compute the stability and the electronic properties of crystalline materials from density-functional theory using the strongly constrained and appropriately normed approximation (SCAN) for the exchange–correlation potential. We show the performance of the developed tool exploring the binary Cs–Te phase space that hosts cesium telluride, a semiconducting material widely used as a photocathode in particle accelerators. Starting from a pool of structures retrieved from open computational material databases, we analyze formation energies as a function of the relative Cs content and for a few selected crystals, we investigate the band structures and density of states unraveling interconnections among the structure, stoichiometry, stability, and electronic properties. Our study contributes to the ongoing research on alkali-based photocathodes and demonstrates that high-throughput calculations based on state-of-the-art first-principles methods can complement experiments in the search for optimal materials for next-generation electron sources.

Impact of Ligand Substitution and Metal Node Exchange in the Electronic Properties of Scandium Terephthalate Frameworks

“…The computational workflow used in this study is implemented in an in-house developed library embedding routines for data mining, HT DFT calculations based on the AiiDA infrastructure, , and postprocessing tools. This package, initially designed for inorganic crystals, has been purposely tailored here to investigate MOFs (see Figure ). The initial input includes structural information about the scaffold, which, in this case, is Sc terephthalate.…”

“…Likewise, the Sc nodes are replaced with Y and Al atoms, giving rise to the final pool of input structures for the DFT calculations. The remaining part of the workflow is equivalent to the one presented in ref ( 43 ), to which we redirect interested readers for further information.…”

“…40−42 The relative structural simplicity of Sc 2 (BDC) 3 makes it a suitable platform for the present computational study based on DFT investigating the structural and electronic properties of Sc terephthalate scaffolds modified by metal-ion substitution and ligand functionalization. By applying an in-house implemented automated workflow for ab initio calculations, 43 we construct 24 structures and analyze their equilibrium geometries as well as their energetic stability at varying metal nodes and molecular functionalization. We discuss the larger impact of the metallic species on the structural properties in contrast with the moderate effect of the ligand substituents, which merely induce some steric hindrance.…”

Advances in data‐assisted high‐throughput computations for material design

“…Given features like interconnected automation and storage modules, flexible workflow design, user‐friendly interaction with computational resources, and a convenient modular plugin design, AiiDA could help users to avoid errors frequently occurring in material computation. Applications of AiiDA are found in the discovery of novel materials with fascinating properties [178,179] …”

Thermodynamic stability and vibrational properties of multi-alkali antimonides

“…Computational research on photocathodes has been boosted by the advent of high-throughput screening methods which have enabled the exploration of large configurational spaces and the identification of optimal compounds for this specific application [26,34,35]. So far, corresponding efforts have been focused mainly on determining relative stability and energy levels without the inclusion of thermodynamic effects.…”