pyGWBSE:a high throughput workflow package for GW-BSE calculations

We develop an open-source python workflow package,pyGWBSE to perform automated first-principles calculations within the GW-BSE(Bethe-Salpeter)framework.GW-BSE is a many body perturbation theory based approach to explore the quasiparticle(QP)and excitonic properties of materials.GW approximation accurately predicts bandgaps of materials by overcoming the bandgap underestimation issue of the more widely used density functional theory(DFT).BSE formalism produces absorption spectra directly comparable with experimental observations.pyGWBSE package achieves complete automation of the entire multi-step GW-BSE computation,including the convergence tests of several parameters that are crucial for the accuracy of these calculations.pyGWBSE is integrated with Wannier90,to generate QP bandstructures,interpolated using the maximally-localized wannier functions.pyGWBSE also enables the automated creation of databases of metadata and data,including QP and excitonic properties,which can be extremely useful for future material discovery studies in the field of ultra-wide bandgap semiconductors,electronics,photovoltaics,and photocatalysis.

Excitonic effects in absorption spectra of carbon dioxide reduction photocatalysts

The formation and disassociation of excitons play a crucial role in any photovoltaic or photocatalytic application.However,excitonic effects are seldom considered in materials discovery studies due to the monumental computational cost associated with the examination of these properties.Here,we study the excitonic properties of nearly 50 photocatalysts using state-of-the-art Bethe–Salpeter formalism.These~50 materials were recently recognized as promising photocatalysts for CO_(2) reduction through a data-driven screening of 68,860 materials.Here,we propose three screening criteria based on the optical properties of these materials,taking excitonic effects into account,to further down select six materials.Furthermore,we study the correlation between the exciton binding energies obtained from the Bethe–Salpeter formalism and those obtained from the computationally much lessexpensive Wannier–Mott model for these chemically diverse~50 materials.This work presents a paradigm towards the inclusion of excitonic effects in future materials discovery for solar-energy harvesting applications.