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Updated: Jun 27, 2026

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Solvent effects on optical properties of molecules: a combined time-dependent density functional theory/effective
Soohaeng Yoo1, Federico Zahariev, Sarom Sok
1Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
Abstract:
A quantum mechanics/molecular mechanics (QM/MM) type of scheme is employed to calculate the solvent-induced shifts of molecular electronic excitations. The effective fragment potential (EFP) method was used for the classical potential. Since EFP has a density dependent functional form, in contrast with most other MM potentials, time-dependent density functional theory (TDDFT) has been modified to combine TDDFT with EFP. This new method is then used to perform a hybrid QM/MM molecular dynamics simulation to generate a simulated spectrum of the n-->pi(*) vertical excitation energy of acetone in vacuum and with 100 water molecules. The calculated water solvent effect on the vertical excitation energy exhibits a blueshift of the n-->pi(*) vertical excitation energy in acetone (Delta omega(1)=0.211 eV), which is in good agreement with the experimental blueshift.
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