BSE@<i>GW</i> Prediction of Charge Transfer Exciton in Molecular Complexes: Assessment of Self-Energy and Exchange-Correlation Dependence
Sampreeti Bhattacharya, Jiachen Li, Weitao Yang, Yosuke Kanai
Abstract
The Bethe–Salpeter equation using the GW approximation to the self-energy (BSE@ GW ) is a computationally attractive method for studying electronic excitation from first principles within the many-body Green’s function theory framework. We examine its dependence on the underlying exchange-correlation (XC) approximation as well as on the GW approximation for predicting the charge transfer exciton formation at representative type-II interfaces between molecular systems of tetrachloro-1,2-benzoquinone (TCBQ) and acene derivatives. For the XC approximation, we consider several widely used generalized gradient approximation (GGA) and hybrid GGA functionals. For the GW self-energy approximation, we examine the recently proposed renormalized singles approach by Yang and coauthors [ J. Phys. Chem. Lett. 2019, 10 (3), 447–452; J. Chem. Theory Comput. 2022, 18, 7570–7585] in addition to other commonly employed approximated GW schemes. We demonstrate a reliable prediction of the charge transfer exciton within the BSE@ GW level of theory.