Ranking the screening efficacy of atomic orbitals

However, in the solid state, the SF driving force and the exciton character are modulated by intermolecular interactions present within different packing arrangements. Within a family of molecules containing the same acene backbone, increasing the number of phenyl side groups is detrimental for the SF driving force in the gas phase. In both the gas phase and solid state, pentacene and its derivatives are more promising than tetracene analogs. Their potential for SF is evaluated with respect to the thermodynamic driving force and the singlet exciton charge transfer character. Using many-body perturbation theory in the GW approximation and the Bethe-Salpeter equation (BSE), we systematically investigate the electronic and excitonic properties of tetracene, pentacene, and their phenylated derivatives in the gas phase and solid state. Only a few materials have been experimentally observed to undergo intermolecular SF, most of which are acenes and their derivatives. Singlet fission (SF), a spin-conserving process where one singlet exciton converts into two triplet excitons, may improve the efficiency of organic photovoltaics. The GW-BSE estimates showed excellent agreement with previously reported experimental results. In this study, the optical absorption spectra and frontier molecular orbitals of these compounds were compared using TDDFT and GW-BSE calculations. This method was used to perform calculations of the excited states of two NIR molecular fluorophores (BTC980 and BTC1070), going beyond TDDFT. In this study, we used the GW approximation combined with the Bethe-Salpeter equation (GW-BSE) implemented in many-body perturbation theory approaches based on density functional theory. However, the size and large excitonic energies of these compounds pose challenges with respect to computational cost and time. The standard approach for these calculations has been time-dependent density functional theory (TDDFT). However, adequate theoretical levels to provide efficient and accurate estimations of the optical and electronic properties of organic NIR-II fluorophores are lacking.

Organic-molecule fluorophores with emission wavelengths in the second near-infrared window (NIR-II, 1000вЂ“1700 nm) have attracted substantial attention in the life sciences and in biomedical applications because of their excellent resolution and sensitivity. Mostly and considerably underestimates the excitation energies as shown for a few molecules. Green's function (G) and the dynamically screened interaction (W) GW/BSE (QSGW/BSE) approach in which orbitals and energies are updated in the We further demonstrate that the quasi-particle self-consistent The total mean absolute error of 0.59 eV in the standard Hartree-Fock (HF)Д«ased eigenvalue GW/BSE approach is reduced to 0.26 eV for 63 triplet states. Random phase approximation (RPA) (in order to ensure best gap and an optimal exciton binding energy), We show that by mixing different screenings into GW and BSE calculated within Now we have evaluated the accuracy of the proposed schemeДЇor triplet states of a set of 20 organic molecules known as the Thiel set. B,, 195115 (2017)) to decrease the typical overestimation of the Hartree-FockД«ased GW/Bethe Salpeter equation (BSE) singlet-singlet excitation energies in We recently proposed a screening mixing many-body ansatz (Phys.

Ranking the screening efficacy of atomic orbitals