TY - JOUR
T1 - Bond-breaking excitations with diverging coupling matrix of response density functional theory from highest-level functionals
AU - van Meer, Robert
AU - Gritsenko, Oleg V.
PY - 2018/6
Y1 - 2018/6
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85048853837&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85048853837&partnerID=8YFLogxK
U2 - 10.1140/epjb/e2018-90088-6
DO - 10.1140/epjb/e2018-90088-6
M3 - Article
AN - SCOPUS:85048853837
VL - 91
SP - 1
EP - 6
JO - European Physical Journal B. Condensed Matter and Complex Systems
JF - European Physical Journal B. Condensed Matter and Complex Systems
SN - 1434-6028
IS - 6
M1 - 122
ER -