A Simple Hubbard Model for the Excited States of Dibenzoterrylene

TL;DR

This paper employs a simplified Hubbard model to analyze the excited electronic states of dibenzoterrylene, providing insights into transition energies, wavefunctions, and singlet-triplet splitting with implications for molecular electronic properties.

Contribution

It introduces a straightforward Hubbard model approach to characterize excited states of DBT, offering new predictions on energy splittings and wavefunction features.

Findings

Predicted singlet-triplet splitting of 0.75 eV

DBT ground state is mainly closed shell with slight radical character

Hubbard interaction minimally affects singlet and triplet states

Abstract

We use a simple Hubbard model to characterize the electronic excited states of the dibenzoterrylene (DBT) molecule; we compute the excited state transition energies and oscillator strengths from the ground state to several singlet excited states. We consider the lowest singlet and triplet states of the molecule, examine their wavefunctions, and compute the density correlation functions that describe these states. We find that the DBT ground state is mostly a closed shell singlet with very slight radical character. We predict a relatively small singlet-triplet splitting of 0.75 eV, which is less than the mid-sized -acenes but larger than literature predictions for this state; this is because the Hubbard interaction makes a very small correction to the singlet and triplet states.