Calculating rate constants for intersystem crossing and internal conversion in the Franck–Condon and Herzberg–Teller approximations

Abstract

Effective and fast algorithms for calculating rate constants for internal conversion (IC) and intersystem crossing (ISC) in the Franck–Condon and Herzberg–Teller approximations have been developed and implemented.

Predicting fluorescence quantum yields for molecules in solution: A critical assessment of the harmonic approximation and the choice of the lineshape function

“…To identify candidate molecules for synthesis, virtual screenings could be performed for identifying the most promising novel compounds with high quantum yields and other desirable properties such as low emission energy in the infrared part of the spectrum. Recently several programs 3,4 were developed for predicting rates for radiative and non-radiative (internal conversion, IC 5,6 , and intersystem crossing, ISC 7,8 ) decays using Fermi's Golden rule. They are based on the idea that the decay processes are slower than thermalization and that the couplings are small.…”

Is either direct photolysis or photocatalysed H-shift of peroxyl radicals a competitive pathway in the troposphere?

“…Note that in the original formula [41], the integral over the absorption band is used, but here it is assumed that the electronic transition energy can be directly used instead. k IC is calculated using the algorithm described in [40,42] with the formula royalsocietypublishing.org/journal/rsos R. Soc. Open Sci.…”

Photophysical properties of the triangular [Au(HNCOH)]3 complex and its dimer

“…Computational studies make estimates of these rate constants on the basis of quantum mechanical principles possible. 43,44 The fluorescence rate from state S 1 can be approximated from oscillator strengths using the Strickler-Berg equation. 45 Spin-orbit coupling has to be considered for transition processes between states of different multiplicity such as ISC and phosphorescence.…”

“…The lifetime and phosphorescence rate of the triplet state can be calculated from the transition strengths. 46 The non-radiative transition rate constants are calculated using a method developed by Valiev et al, 43,44 where the expression for the rate constant of internal conversion is…”

“…45 The phosphorescence rates (k phos ) were calculated using perturbation theory (PT) with Turbomole 49,50,52 at the SOC-PT-CC2 level 46 using the TD-DFT geometries. The IC and ISC rate constants (k IC and k ISC ) were calculated within the Herzberg-Teller approximation 77 using the methodology developed by Valiev et al 43,44 The IC rate constant from the T 1 state to the S 0 ground state was calculated from the state mixing coefficients and the excitation energies using the formula by Artyukhov et al 47,48 3 Results and discussion…”