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.

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