Bond-breaking excitations with diverging coupling matrix of response density functional theory from highest-level functionals

Robert van Meer, Oleg V. Gritsenko*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

Bond-breaking excitations ωα are the problematic case of adiabatic time-dependent density functional theory (TDDFT). The calculated ωα erroneously vanishes with the bond elongation, since the Hartree-exchange-correlation kernel and the corresponding response coupling matrix K of standard approximations lack the characteristic divergence in the dissociation limit. In this paper an approximation for K is proposed constructed from the highest-level functionals, in which both occupied and virtual Kohn-Sham orbitals participate with the weights wp. The latter provide the correct divergence of K in the limit of dissociating two-electron bond. The present K brings a decisive contribution to the energy of the 1Σu + in the prototype H2 molecule calculated for various H-H separations. At shorter separations it improves ωα compared to the zero-order TDDFT estimate, while at the largest separation it reproduces near-saturation of the reference excitation energy.

Original languageEnglish
Article number122
Pages (from-to)1-6
Number of pages6
JournalEuropean Physical Journal B
Volume91
Issue number6
Early online date18 Jun 2018
DOIs
Publication statusPublished - Jun 2018

Fingerprint Dive into the research topics of 'Bond-breaking excitations with diverging coupling matrix of response density functional theory from highest-level functionals'. Together they form a unique fingerprint.

Cite this