Journal ArticleDOI
An efficient approach for the calculation of Franck-Condon integrals of large molecules.
Marc Dierksen,Stefan Grimme +1 more
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TLDR
With this approach accurate calculations of FCIs are feasible also for large molecules encountered in "real-life" chemistry, especially biochemistry and material science.Abstract:
A general and efficient approach for the calculation of Franck–Condon integrals (FCIs) of large molecules is presented. In a first step, by exploiting the diagonally dominant and sparse structure of the Duschinsky matrix, a model system is constructed for which the Duschinsky matrix takes a block-diagonal form. For each of these blocks separately, the FCIs are calculated discarding all below a certain threshold. From those integrals retained the FCIs of the model system are obtained by simple multiplication. These serve as an estimate for the FCIs of the exact system which are calculated for those integrals which lie above a certain threshold. By systematically decreasing the threshold, the simulation can be reliably converged to the exact result with an arbitrary accuracy. Using this scheme, a considerable reduction of the number of FCIs which have to be calculated is achieved which leads to an improved scaling behavior of the computational effort with system size. The approach has been tested thoroughly for a set of molecules including difficult cases. For the larger systems a speedup of up to three orders of magnitude compared to an exact calculation is observed while the errors can be kept negligible. With this approach accurate calculations of FCIs are feasible also for large molecules encountered in “real-life” chemistry, especially biochemistry and material science.read more
Citations
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Spin–orbit coupling and intersystem crossing in molecules
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Spin-Vibronic Mechanism for Intersystem Crossing
TL;DR: The theory and fundamental principles of the spin-vibronic mechanism for ISC are presented, followed by empirical rules to estimate the rate of ISC within this regime.
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Effective method for the computation of optical spectra of large molecules at finite temperature including the Duschinsky and Herzberg–Teller effect: The Qx band of porphyrin as a case study
TL;DR: The method presented here automatically selects the relevant vibronic contributions to the spectrum, independent of their frequency, and it is able to provide fully converged spectra with a modest computational requirement, performing for the first time an exact treatment of vibrations in harmonic approximation.
Journal ArticleDOI
Effective method to compute Franck-Condon integrals for optical spectra of large molecules in solution.
TL;DR: A new method is presented for the computation of vibrationally resolved optical spectra of large molecules, including the Duschinsky rotation of the normal modes, able to provide fully converged spectra with a quite modest computational time, both in vacuo and in condensed phase.
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Toward effective and reliable fluorescence energies in solution by a new state specific polarizable continuum model time dependent density functional theory approach
TL;DR: A state specific (SS) model for the inclusion of solvent effects in time dependent density functional theory (TD-DFT) computations of emission energies has been developed and coded in the framework of the so called polarizable continuum model (PCM).
References
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