Chemistry Publications
Document Type
Article
Publication Date
8-6-2019
Journal
Journal of Chemical Theory and Computation
Volume
15
Issue
9
First Page
4956
Last Page
4964
URL with Digital Object Identifier
https://doi.org/10.1021/acs.jctc.9b00618
Abstract
Calculation of vertical excitation energies by the adiabatic linear-response time-dependent density-functional theory (TDDFT) requires static Kohn–Sham potentials and exchange–correlation kernels. When these quantities are derived from standard density-functional approximations (DFA), mean absolute errors (MAE) of the method are known to range from 0.2 eV to over 1 eV, depending on the functional and type of excitation. We investigate how the performance of TDDFT varies when increasingly accurate exchange–correlation potentials derived from Hartree–Fock (HF) and post-HF wavefunctions are combined with different approximate kernels. The lowest MAEs obtained in this manner for valence excitations are about 0.15–0.2 eV, which appears to be the practical limit of the accuracy of TDDFT that can be achieved by improving the Kohn–Sham potentials alone. These findings are consistent with previous reports on the benefits of accurate exchange–correlation potentials in TDDFT, but provide new insights and afford more definitive conclusions.
Notes
This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Journal of Chemical Theory and Computation, copyright © American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/acs.jctc.9b00618