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Updated: Jul 21, 2025
08:04
Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
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Efficient Calculation of the Dispersion Energy for Multireference Systems with Cholesky Decomposition: Application to
Michał Hapka1, Agnieszka Krzemińska2, Marcin Modrzejewski1
1Faculty of Chemistry, University of Warsaw, ul. L. Pasteura 1, 02-093 Warsaw, Poland.
The Journal of Physical Chemistry Letters
|July 26, 2023
Summary
We developed a new algorithm for predicting dispersion interactions in excited-state complexes. This method accurately calculates dispersion energy, revealing it as a key stabilizing force in excited-state dimers.
Area of Science:
- Quantum Chemistry
- Computational Chemistry
- Spectroscopy
Background:
- Accurate prediction of dispersion interactions in excited-state complexes is challenging.
- Electron correlation effects complicate these calculations.
- Existing methods struggle with simultaneous consideration of these effects.
Purpose of the Study:
- To develop an efficient algorithm for computing dispersion energy in excited-state complexes.
- To enable accurate calculations for systems with arbitrary spin.
- To investigate the role of dispersion forces in stabilizing excited-state dimers.
Main Methods:
- Developed a novel algorithm for dispersion energy computation.
- Algorithm employs Cholesky decomposition of Coulomb integrals.
- Utilizes a recursive formula for density response functions.
- Applied within multiconfigurational symmetry adapted perturbation theory (SAPT(MC)).
Main Results:
- The algorithm exhibits a favorable scaling of O(N^5) with system size.
- Numerical applications were performed on dimers with localized excitons.
- SAPT(MC) analysis quantified dispersion energy contributions.
Conclusions:
- The proposed algorithm provides an accurate and efficient method for dispersion energy prediction.
- Dispersion energy can be the dominant stabilizing factor in excited-state dimers.
- This work advances the understanding of intermolecular interactions in excited states.
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