Issue 15, 2015

Singlet–triplet gaps in polyacenes: a delicate balance between dynamic and static correlations investigated by spin–flip methods

Abstract

Over the last few years people have been interested in the process of singlet fission, owing to its relevance to solar cell technology. The energetics of singlet fission is intimately related to singlet–triplet (ST) gaps and energies of singlet excited states. However, accurate calculations of ST gaps in polyacenes are complicated due to near degeneracies in the π orbitals, and therefore, have been quite challenging. The spin–flip equation-of-motion coupled-cluster (SF-EOM-CC) and its perturbative approximation have been shown to correctly treat situations involving electronic degeneracies and near degeneracies. In this work, we use various spin–flip methods to benchmark the ST gaps of small polyacenes and show that the error in the ST gaps with respect to the experiment is small and does not increase appreciably with the system size. The diradical and polyradical character of the polyacene ground states increase with the system size. However, for the small polyacenes the open-shell character of the ground state is still small enough to be treated using single reference methods.

Graphical abstract: Singlet–triplet gaps in polyacenes: a delicate balance between dynamic and static correlations investigated by spin–flip methods

Supplementary files

Article information

Article type
Paper
Submitted
23 ربيع الأول 1436
Accepted
13 جمادى الأولى 1436
First published
13 جمادى الأولى 1436

Phys. Chem. Chem. Phys., 2015,17, 9849-9856

Singlet–triplet gaps in polyacenes: a delicate balance between dynamic and static correlations investigated by spin–flip methods

C. U. Ibeji and D. Ghosh, Phys. Chem. Chem. Phys., 2015, 17, 9849 DOI: 10.1039/C5CP00214A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements