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The magnitude of the renormalization of the band gaps due to zero-point motions of the lattice is calculated for 18 semiconductors, including diamond and silicon. This particular collection of semiconductors constitute a wide range of band gaps and atomic masses. The renormalized electronic structures are obtained using stochastic methods to sample the displacement related to the vibrations in the lattice. Specifically, a recently developed one-shot method is utilized where only a single calculation is needed to get similar results as the one obtained by standard Monte-Carlo sampling. In addition, a fast real-space GW method is employed and the effects of G0W0 corrections on the renormalization are also investigated. We find that the band-gap renormalizations inversely depend on the mass of the constituting ions, and that for the majority of investigated compounds the G0W0 corrections to the renormalization are very small and thus not significant.

A prerequisite to characterize magnetic materials is the capability to describe systems containing unpaired electrons. In this study, we benchmark the one-shot GW ( G 0 W 0 ) on top of different unrestricted mean-field solutions for open-shell molecules using Dunning’s correlation-consistent basis sets expanded in terms of Gaussian functions. We find that the G 0 W 0 correction to hybrid functionals provides reasonably accurate results for the ionization energies of open-shell systems when compared to those obtained from high-level ab initio methods. Moreover, the quality of the G 0 W 0 exchange–correlation approximation is evaluated by the discrepancy between the ionization energy of the neutral molecules and the electron affinity of the corresponding cations. Furthermore, we assess the capability of the GW to reproduce the correct energy ordering of molecular spin–orbitals. To such an aim, we thoroughly discuss three open-shell molecules CN, NH 2 , and O 2 , for which approximate functionals fail to correctly capture the single-electron spectrum. Particularly, we demonstrate that the overestimation of the exchange energy in the studied spin–orbitals is reduced by the GW dynamic correlation term, restoring the molecular orbital ordering. Interestingly, we find that deviations of the exchange and correlation energies, in comparison with our ab initio reference, can be very different for molecular orbitals with different symmetry, e.g. σ and π -type orbitals.

Based on density functional theory (DFT), the GW approximation and Bethe–Salpeter equation (BSE), we performed a theoretical calculation to study the electronic and optical properties of penta-graphene (PG) monolayers. Our findings reveal that PG behaves as a semiconductor with an indirect band gap of 2.27 eV at the DFT-GGA level. By incorporating the GW approximation based on many-body perturbation theory, we observed an increase in the band gap, resulting in a quasi-direct band gap of 4.53 eV. Furthermore, we employed the G 0 W 0 -RPA and G 0 W 0 -BSE approximations to compute the optical spectra of the monolayer in the absence and in the presence of electron–hole interaction, respectively. The results indicate that the inclusion of electron–hole interactions leads to a red-shift of the absorption spectrum towards lower energies compared to the spectrum obtained from the G 0 W 0 -RPA approximation. Notably, the optical absorption spectra are predominantly governed by the first bound exciton, characterized by a significant binding energy of 2.07 eV. Our results suggest that the PG monolayer, with its wider band gap and enhanced excitonic effects, is potentially a suitable candidate for the design and fabrication of optoelectronic components.

Since the definitions of the two-dimensional (2D) optical absorption coefficient and photoconductivity are independent of the thickness of 2D materials, they are more suitable than the dielectric function to describe the optical properties of 2D materials. Based on the many-body GW method and the Bethe–Salpeter equation, we calculated the quasiparticle electronic structure, optical absorbance, and complex photoconductivity of 2D InSe from a single layer (1L) to three layers (3L). The calculation results show that the energy difference between the direct and indirect band gaps in 1L, 2L, and 3L InSe is so small that strain can readily tune its electronic structure. The 2D optical absorbance results calculated taking into account exciton effects show that light absorption increases rapidly near the band gap. Strain modulation of 1L InSe shows that it transforms from an indirect bandgap semiconductor to a direct bandgap semiconductor in the biaxial compressive strain range of −1.66 to −3.60%. The biaxial compressive strain causes a slight blueshift in the energy positions of the first and second absorption peaks in monolayer InSe while inducing a measurable redshift in the energy positions of the third and fourth absorption peaks.

We study the electronic structure and thermoelectric properties of recently synthesized CoAsSb. The calculated bandgap becomes more accurate for increasingly complex electronic structure methods: generalized gradient approximation, hybrid functionals, self-consistent linearized quasiparticle GW method (LQSGW), and LQSGW with simplified vertex corrections. By equating the bandgaps of each method from a rigid shift of the bands, we evaluate the contributions made to thermoelectric properties beyond the bandgap. In doing so, we evaluate the efficacy of a common practice: a rigid shift applied to less costly electronic structure methods to gain some accuracy of the more costly methods. We find that while the shift made the Seebeck coefficients much closer to one another than from the original electronic structures, there remain differences in the Goldsmid–Sharp (thermoelectric) bandgap between the methods and from the intended electronic bandgap. Additionally, some lasting differences in temperature dependence remain between the methods.

The quest for novel materials with extraordinary electronic and plasmonic properties is an ongoing pursuit in the field of materials science. The dataset provides the results of a computational study that used ab initio and semi-analytical computations to model freestanding nanosystems. We delve into the world of ribbon-like materials, specifically graphene nanoribbons, silicene nanoribbons, and germanene nanoribbons, comparing their electronic and plasmonic characteristics. Our research reveals a myriad of insights, from the tunability of band structures and the influence of an atomic number on electronic properties to the adaptability of nanoribbons for optoelectronic applications. Further, we uncover the promise of these materials for biosensing, demonstrating their plasmon frequency tunability based on charge density and Fermi velocity modification. Our findings not only expand the understanding of these quasi-1D materials but also open new avenues for the development of cutting-edge devices and technologies. This data presentation holds immense potential for future advancements in electronics, optics, and molecular sensing.

The GW method is a standard method to calculate the electronic band structure from first principles. It has been applied to a large variety of semiconductors and insulators but less often to metallic systems, in particular, with respect to a self-consistent employment of the method. In this work, we take a look at all-electron quasiparticle self-consistent GW (QSGW) calculations for simple metals (alkali and alkaline earth metals) based on the full-potential linearized augmented-plane-wave approach and compare the results to single-shot (i.e., non-selfconsistent) G0W0 calculations, density-functional theory (DFT) calculations in the local-density approximation, and experimental measurements. We show that, while DFT overestimates the bandwidth of most of the materials, the GW quasiparticle renormalization corrects the bandwidths in the right direction, but a full self-consistent calculation is needed to consistently achieve good agreement with photoemission data. The results mainly confirm the common belief that simple metals can be regarded as nearly free electron gases with weak electronic correlation. The finding is particularly important in light of a recent debate in which this seemingly established view has been contested.

Many-body perturbation theory based on density-functional theory calculations is used to determine the quasiparticle band structures and the dielectric functions of the isomorphic ferroelectrics rubidium titanyl phosphate (RbTiOPO4) and potassium titanyl arsenide (KTiOAsO4). Self-energy corrections of more than 2 eV are found to widen the transport band gaps of both materials considerably to 5.3 and 5.2 eV, respectively. At the same time, both materials are characterized by strong exciton binding energies of 1.4 and 1.5 eV, respectively. The solution of the Bethe–Salpeter equation based on the quasiparticle energies results in onsets of the optical absorption within the range of the measured data.

Methane photolysis is a very important initiation reaction from the perspective of hydrogen production for alternative energy applications. In our recent work, we demonstrated using our recently developed novel method, non-adiabatic excited-state time-dependent GW (TDGW) molecular dynamics (MD), how the decomposition reaction of methane into a methyl radical and a hydrogen atom was captured accurately via the time-tracing of all quasiparticle levels. However, this process requires a large amount of photoabsorption energy (PAE ∼10.2 eV). Moreover, only one hydrogen atom is produced via a single photon absorption. Transition metal atoms can be used as agents for photochemical reactions, to reduce this optical gap and facilitate an easier pathway for hydrogen production. Here, we explore the photolysis of methane in the presence of a Ni atom by employing TDGW-MD. We show two possibilities for hydrogen-atom ejection with respect to the location of the Ni atom, towards the Ni side or away from it. We demonstrate that only the H ejection away from the Ni side facilitates the formation of a hydrogen molecule with the quasiparticle level corresponding to it having an energy close to the negative ionization potential of an isolated H2 molecule. This is achieved at a PAE of 8.4 eV which is lower compared to that of pristine methane. The results obtained in this work are an encouraging step towards transition metal-mediated hydrogen production via photolysis of hydrocarbons.

The ability of a material to perform surface catalysis depends on the electronic structure features at the surface. Recent experiments on Fe 2 O 3 , one of the most studied water oxidation catalysts show that surface states may originate from adsorbed reaction intermediates that are cardinal for catalysis. Our recent theoretical DFT+U calculations confirm this hypothesis. In this paper, in order to account for more accurate electronic structure of the surface, we perform a one-shot GW calculation from a DFT+U wavefunction. We find that G 0 W 0 overestimates the energy position of surface states, but provides good qualitative features of the surface’s electronic structure. Graphical Abstract