Review
Chemistry, Multidisciplinary
Maciej Bieniek, Katarzyna Sadecka, Ludmila Szulakowska, Pawel Hawrylak
Summary: This article presents a theory of excitons in two-dimensional semiconductors and discusses their electronic structure, energy levels, and optical response. It also explores the effects of electron-electron interactions, band nesting, and dielectric environment on the excitonic spectra.
Article
Chemistry, Physical
Timothy J. H. Hele, Bartomeu Monserrat, Antonios M. Alvertis
Summary: This study demonstrates that accounting for nuclear quantum motion in calculations of excited state energies can significantly improve agreement with experiment, with the redshift reaching up to 1.36 eV compared to static calculations that only consider electronic effects. Furthermore, the impact of nuclear quantum motion on excited state energies varies depending on molecular size, with smaller molecules showing larger redshifts.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Christof Holzer, Ansgar Pausch, Wim Klopper
Summary: The GW approximation and the Bethe-Salpeter equation have been successfully implemented in the Turbomole program package for computations of molecular systems in a strong magnetic field. Complex-valued London orbitals are used as basis functions to ensure gauge-invariant computational results. Benchmarking against triplet excitation energies of 36 small to medium-sized molecules validated the accuracy of the implementation. Additionally, the tetracene molecule exhibits a dramatic color change from orange to green when subjected to magnetic fields ranging from 0 to 9,000 T perpendicular to the molecular plane.
FRONTIERS IN CHEMISTRY
(2021)
Article
Chemistry, Physical
Arno Forster, Erik van Lenthe, Edoardo Spadetto, Lucas Visscher
Summary: We present an all-electron, atomic orbital-based, two-component implementation of the GW approximation for closed-shell molecules. Our algorithm accurately predicts the first ionization potentials of molecules with heavy elements and exhibits good performance compared to other codes. It has high practical value due to its computational efficiency and accuracy.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Yeongsu Cho, Sylvia J. Bintrim, Timothy C. Berkelbach
Summary: This article introduces a simplified approach to excited-state calculations within the GW approximation to the self-energy and the Bethe-Salpeter equation (BSE), called sGW/sBSE. The method is tested and verified for its performance in calculating ionization potential and excitation energies of molecules. It demonstrates small storage requirements and computational timing when used for larger systems.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Materials Science, Multidisciplinary
Guang Yang, Wenxin Xu, Shang-Peng Gao
Summary: This study investigates the structural, electronic, and optical properties of ultrathin CeO2, providing insights into its phonon dispersion, band structure, density of states, and optical performance. The research reveals that monolayer CeO2 exhibits excellent in-plane optical performance in the ultraviolet region, making it suitable for photocatalytic and optoelectronic applications.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Yi Yao, Dorothea Golze, Patrick Rinke, Volker Blum, Yosuke Kanai
Summary: We present an accurate computational approach to calculate absolute K-edge core electron excitation energies as measured by X-ray absorption spectroscopy. The method is based on the Bethe-Salpeter equation and GW quasiparticle energies, and takes into account various numerical approximations and basis sets. The results show excellent agreement with experimental data, demonstrating the high accuracy of the method.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Biochemistry & Molecular Biology
Jing Li, Valerio Olevano
Summary: The study investigates the photo-absorption and exciton structures of Chl a and b in their in vivo conformations using the Bethe-Salpeter equation. The BSE optical absorption spectra are in good agreement with the experiment, and the BSE explains the experimental evidence of multiple Chla forms.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
(2022)
Article
Physics, Multidisciplinary
K. Sadecka
Summary: The study investigates the electronic and excitonic properties of MoSe2/WSe2 heterostructure using effective mass approximation and Bethe-Salpeter theory. The research reveals rich optical spectrum and different excitonic states in the heterostructure.
ACTA PHYSICA POLONICA A
(2022)
Article
Chemistry, Physical
Enzo Monino, Pierre-Francois Loos
Summary: By recasting the non-linear frequency-dependent GW quasiparticle equation into a linear eigenvalue problem, this study explains the occurrence of multiple solutions and unphysical discontinuities in various physical quantities computed within the GW approximation. The GW self-energy is treated as an effective Hamiltonian, which reveals the key signatures of strong correlation in the (N +/- 1)-electron states and their direct relation to the intruder state problem. A regularization procedure inspired by the similarity renormalization group is proposed to avoid these issues and accelerate the convergence of partially self-consistent GW calculations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Tathagata Biswas, Arunima K. Singh
Summary: We have developed an open-source python workflow package, pyGWBSE, for automated first-principles calculations within the GW-BSE framework. This package achieves complete automation of the entire multi-step GW-BSE computation and can be integrated with Wannier90 for QP bandstructure generation. It also enables the creation of metadata and data databases, including QP and excitonic properties, which are useful for future material discovery studies.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Yi Yao, Dorothea Golze, Patrick Rinke, Volker Blum, Yosuke Kanai
Summary: This article presents an accurate computational approach to calculate absolute K-edge core electron excitation energies using numeric atom-centered orbitals (NAOs). The method is validated by comparing the results with experimental data and demonstrates excellent agreement.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Physics, Condensed Matter
Ezekiel Oyeniyi
Summary: In this study, electronic and optical properties of Mg3XN (X = P, As, Sb, Bi) antiperovskite materials were investigated using GW approximations and the solution to the Bethe Salpeter Equation. It was found that different X elements in Mg3XN materials result in direct or indirect band gaps, and the values of the band gaps were obtained. Furthermore, the spin-orbit coupling has some impact on the band gaps of Mg3SbN and Mg3BiN, and the optical properties revealed the potential applications of APs in solar cell and optoelectronic devices.
SOLID STATE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Laurenz Monzel, Christof Holzer, Wim Klopper
Summary: The GW method is popular for determining vertical ionization energies in molecular systems, but it may be computationally intensive depending on the formalism and range of orbitals used. Correlated natural virtual orbitals based on MP2 and direct MP2 correlation energies are implemented to alleviate the computational scaling issue. These correlated NVOs significantly improve efficiency for larger molecular systems and basis sets.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Meisam Rezaei, Serdar Ogut
Summary: The photoelectron spectra of early 3d-transition metal dioxide anions were calculated using different levels of DFT theory and GW approximation methods. The study found that using G(0)W(0) with a PBE0 starting point consistently provided good agreement with experimentally measured binding energies. Conversely, one-shot GW calculations with a PBE starting point performed poorly in predicting electron removal energies.
JOURNAL OF CHEMICAL PHYSICS
(2021)
