Efficient periodic resolution-of-the-identity Hartree–Fock exchange method with k-point sampling and Gaussian basis sets

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(6)

Published: Feb. 14, 2024

Simulations of condensed matter systems at the hybrid density functional theory level pose significant computational challenges. The elevated costs arise from non-local nature Hartree–Fock exchange (HFX) in conjunction with necessity to approach thermodynamic limit. In this work, we address these issues development a new efficient method for calculation HFX periodic systems, employing k-point sampling. We rely on local atom-specific resolution-of-the-identity scheme, use atom-centered Gaussian type orbitals, and truncation Coulomb interaction limit complexity. Our real-space exhibits scaling that is, worst, linear number k-points. Issues related basis set diffuseness are effectively addressed through auxiliary matrix method. report implementation CP2K software package, as well accuracy performance benchmarks. This demonstrates excellent agreement equivalent Γ-point supercell calculations terms relative energies nuclear gradients. Good strong weak performances, graphics processing unit (GPU) acceleration, make promising candidate high-performance computing.

Language: Английский

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Excitations in layered materials from a non-empirical Wannier-localized optimally- tuned screened range-separated hybrid functional

npj Computational Materials, Journal Year: 2024, Volume and Issue: 10(1)

Published: Dec. 19, 2024

Accurate prediction of electronic and optical excitations in van der Waals (vdW) materials is a long-standing challenge for density functional theory. The recent Wannier-localized optimally-tuned screened range-separated hybrid (WOT-SRSH) has proven successful non-empirical determination band gaps absorption spectra covalent ionic crystals. However, vdW the tuning material- structure-dependent parameters only been attained semi-empirically. Here, we present WOT-SRSH approach applicable to materials, with optimal transferable between monolayer bulk. We apply this methodology prototypical materials: black phosphorus, molybdenum disulfide, hexagonal boron nitride (in latter case including zero-point renormalization). show that consistently achieves accuracy levels comparable experiments many-body perturbation theory (MBPT) calculations structures spectra, both on its own as an starting point MBPT calculations.

Language: Английский

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Validation of the GreenX library time-frequency component for efficient GW and RPA calculations

Physical review. B./Physical review. B, Journal Year: 2024, Volume and Issue: 109(24)

Published: June 3, 2024

Electronic structure calculations based on many-body perturbation theory [e.g., GW or the random-phase approximation (RPA)] require function evaluations in complex time and frequency domain, for example, inhomogeneous Fourier transforms analytic continuation from imaginary axis to real axis. For transforms, time-frequency component of GreenX library provides grids that can be utilized low-scaling RPA implementations. In addition, adoption compact provided by our also reduces computational overhead implementations with conventional scaling. this paper, we present benchmark using different codes (FHI-aims, CP2K, ABINIT) molecules, two-dimensional materials solids. Very small integration errors are observed when 30 points test cases, namely $<{10}^{\ensuremath{-}8}$ eV/electron correlation energies, $\ensuremath{\le}10$ meV $GW$ quasiparticle energies.

Language: Английский

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Why Does the GW Approximation Give Accurate Quasiparticle Energies? The Cancellation of Vertex Corrections Quantified

The Journal of Physical Chemistry Letters, Journal Year: 2024, Volume and Issue: unknown, P. 12526 - 12534

Published: Dec. 13, 2024

Hedin's GW approximation to the electronic self-energy has been impressively successful in calculating quasiparticle energies, such as ionization potentials, electron affinities, or band structures. The success of this fairly simple ascribed cancellation so-called vertex corrections that go beyond approximation. This claim is mostly based on past calculations using within crude local-density Here, we explore a wide variety nonlocal polarizability and self-energy, first-order approximations infinite summations all orders. In particular, use vertices statically screened interactions like Bethe–Salpeter equation. We demonstrate realistic molecular systems two equation essentially compensate. further show consistency between crucial for obtaining properties. finally consider increasingly large clusters extrapolate our conclusions about compensation would hold extended systems.

Language: Английский

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First-principles excitons in periodic systems with Gaussian density fitting and Ewald potential functions

Physical Review Research, Journal Year: 2025, Volume and Issue: 7(1)

Published: Feb. 12, 2025

Excitons, namely, neutral excitations in a system of electrons arising from the electron-hole interaction, are often essential to explain optical measurements materials. They governed by Bethe-Salpeter equation, which can be cast into matrix form that is formally analogous one for at mean-field level. However, constructing corresponding excitonic Hamiltonian practice challenging, specially computational perspective if wishes surpass effective models. Methods enable such calculations different density-functional theory frameworks currently available are, therefore, convenient. In this work, we present an approach solve BSE starting self-consistent calculation any nonmetallic solid evaluating kernel real space with localized, Gaussian-type basis. It based on Gaussian density fitting or resolution identity approximation reduce initial quartic scaling basis dimension, combination use Ewald-type potential functions automatically sum conditionally convergent lattice series. The method inherits features localized basis, particular reduced requirements due small and tunable Hilbert-space natural adaptation lower-dimensional systems possibility evaluate elements exactly. As illustration implementation, provide examples exciton spectra absorption some paradigmatic 2D 3D materials where single-particle fails qualitatively. Published American Physical Society 2025

Language: Английский

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Solving multipole challenges in the GW100 benchmark enables precise low-scaling GW calculations

Physical review. B./Physical review. B, Journal Year: 2024, Volume and Issue: 110(12)

Published: Sept. 23, 2024

Language: Английский

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Choice of Layering and Band Alignment in 2D Heterostructures

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 21, 2024

Heterostructures are ubiquitous in many optoelectronic devices and as photocatalysts. One of the key features a heterojunction is proper band alignment between two materials. Estimation correct relative positions with density functional theory (DFT)-based electronic structure calculations often constrained by accuracy cost associated various DFT functionals. In this study, we introduce novel computational approach that achieves alignments closely matching experimental results widely used PBE functional. We specifically examine well-documented MoO3/MoS2 system, type-II heterojunction. our setup, MoS2 layers kept they are, but for MoO3, individual chosen differently. These alternative have higher surface energy, hence, edges than those conventional layers. This shift MoO3 changes from type-III to experimentally observed character. also extend strategy additional systems, demonstrating its versatility effectiveness.

Language: Английский

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Deterministic and Faster GW Calculations with a Reduced Number of Valence States: O(N² ln N) Scaling in the Plane-Waves Formalism

Journal of Chemical Theory and Computation, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 19, 2024

We introduce a method for reducing the number of valence states entering calculation screened Coulomb interaction W in GW calculations. In this way, denoting with N generic size system, computational cost is brought from typical O(N4) to more favorable O(N2 ln N). The becomes effective large model structures. For enhancing potentialities our scheme, we combined it linear-response approach, which can exploit symmetries simulation cell direct space. registered quadratic scaling up than thousand atoms an almost 10-fold speed-up respect standard implementation. Our scheme be extended any linear response calculation.

Language: Английский

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