Electron-Affinity Time-Dependent Density Functional Theory: Formalism and Applications to Core-Excited States

• URL: http://arxiv.org/abs/2205.08658v3
• Date: Mon, 19 Sep 2022 18:02:01 GMT
• Title: Electron-Affinity Time-Dependent Density Functional Theory: Formalism and Applications to Core-Excited States
• Authors: Kevin Carter-Fenk, Leonardo A. Cunha, Juan E. Arias-Martinez, Martin Head-Gordon
• Abstract summary: The particle-hole interaction problem is longstanding within time-dependent density functional theory. We derive a linear-response formalism that uses optimized orbitals of the n-1-electron system as reference. Our approach is an exact generalization of the static-exchange approximation and reduces errors in TDDFT XAS by orders of magnitude.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The particle-hole interaction problem is longstanding within time-dependent density functional theory (TDDFT) and leads to extreme errors in the prediction of K-edge X-ray absorption spectra (XAS). We derive a linear-response formalism that uses optimized orbitals of the n-1-electron system as reference, building orbital relaxation and a proper hole into the initial density. Our approach is an exact generalization of the static-exchange approximation that ameliorates particle-hole interaction error associated with the adiabatic approximation and reduces errors in TDDFT XAS by orders of magnitude. With a statistical performance of just 0.5 eV root-mean-square error and the same computational scaling as TDDFT under the core-valence separation approximation, we anticipate that this approach will be of great utility in XAS calculations of large systems.

Related papers

• Learning Equivariant Non-Local Electron Density Functionals [51.721844709174206]
  We introduce Equivariant Graph Exchange Correlation (EG-XC), a novel non-local XC functional based on equivariant graph neural networks. EG-XC combines semi-local functionals with a non-local feature density parametrized by an equivariant nuclei-centered point cloud representation. We find EG-XC to accurately reconstruct gold-standard' CCSD(T) energies on MD17.
  arXiv  Detail & Related papers  (2024-10-10T14:31:45Z)
• Relativistic EELS scattering cross-sections for microanalysis based on Dirac solutions [2.3421105223430483]
  electron energy-loss spectroscopy (EELS) comes from the complex inelastic scattering process. To quantify EELS, the common practice is to compare the cross-sections integrated within an energy window. We make these tabulated GOS available under an open-source license to the benefit of both academic users as well as allowing integration into commercial solutions.
  arXiv  Detail & Related papers  (2024-05-16T14:46:34Z)
• Non-Parametric Learning of Stochastic Differential Equations with Non-asymptotic Fast Rates of Convergence [65.63201894457404]
  We propose a novel non-parametric learning paradigm for the identification of drift and diffusion coefficients of non-linear differential equations. The key idea essentially consists of fitting a RKHS-based approximation of the corresponding Fokker-Planck equation to such observations.
  arXiv  Detail & Related papers  (2023-05-24T20:43:47Z)
• Orbital-free functional with sub-milliHartree errors for slabs [0.0]
  We derive the exact leading corrections to the Thomas-Fermi kinetic energy approximation for Kohn-Sham electrons for slabs. This expansion approximation includes crucial quantum oscillations missed by standard semilocal density functionals.
  arXiv  Detail & Related papers  (2023-03-22T15:21:06Z)
• Electronic excitations of the charged nitrogen-vacancy center in diamond obtained using time-independent variational density functional calculations [0.0]
  A direct orbital optimization method is used to perform variational density functional calculations of a prototypical defect in diamond. Results are remarkably good agreement with high-level, many-body calculations as well as available experimental estimates. The approach is found to be a promising tool for studying electronic excitations of point defects in solids.
  arXiv  Detail & Related papers  (2023-03-07T12:09:16Z)
• D4FT: A Deep Learning Approach to Kohn-Sham Density Functional Theory [79.50644650795012]
  We propose a deep learning approach to solve Kohn-Sham Density Functional Theory (KS-DFT) We prove that such an approach has the same expressivity as the SCF method, yet reduces the computational complexity. In addition, we show that our approach enables us to explore more complex neural-based wave functions.
  arXiv  Detail & Related papers  (2023-03-01T10:38:10Z)
• Kernel-based off-policy estimation without overlap: Instance optimality beyond semiparametric efficiency [53.90687548731265]
  We study optimal procedures for estimating a linear functional based on observational data. For any convex and symmetric function class $mathcalF$, we derive a non-asymptotic local minimax bound on the mean-squared error.
  arXiv  Detail & Related papers  (2023-01-16T02:57:37Z)
• Faster spectral density calculation using energy moments [77.34726150561087]
  We reformulate the recently proposed Gaussian Integral Transform technique in terms of Fourier moments of the system Hamiltonian. One of the main advantages of this framework is that it allows for an important reduction of the computational cost.
  arXiv  Detail & Related papers  (2022-11-01T23:57:58Z)
• Computing X-ray absorption spectra from linear-response particles atop optimized holes [0.0]
  State specific orbital optimized density functional theory (OO-DFT) methods can attain semiquantitative accuracy for predicting X-ray absorption spectra of closed-shell molecules. We present an approach to generate an approximate core-excited state density for use with the ROKS energy ansatz. This hybrid approach can be viewed as a DFT generalization of the static-exchange (STEX) method, and can attain $sim 0.6$ eV RMS error for the K-edges of C-F.
  arXiv  Detail & Related papers  (2022-03-25T09:26:25Z)
• The Exact Second Order Corrections and Accurate Quasiparticle Energy Calculations in Density Functional Theory [0.8057006406834467]
  We develop a second order correction to commonly used density functional approximations (DFA) For small and medium-size molecules, this correction leads to ground-state orbital energies that are highly accurate approximation to the corresponding quasiparticle energies. It provides excellent predictions of ionization potentials, electron affinities, photoemission spectrum and photoexcitation energies beyond previous approximate second order approaches.
  arXiv  Detail & Related papers  (2021-06-18T21:24:21Z)
• Probing eigenstate thermalization in quantum simulators via fluctuation-dissipation relations [77.34726150561087]
  The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems. Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations. Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
  arXiv  Detail & Related papers  (2020-07-20T18:00:02Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.