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Updated: Jun 10, 2026

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Electronic excitation energy calculation by the fragment molecular orbital method with three-body effects
1Fundamental Technology Research Center, Honda R&D Co., Ltd., 1-4-1 Chuo, Wako-shi, Saitama 351-0193, Japan. mahito_chiba@n.f.rd.honda.co.jp
Abstract:
A scheme for full quantum electronic excited state calculation is proposed that is based on the fragment molecular orbital (FMO) method with three-body effects. The accuracy and efficiency of this scheme is checked by calculating the excitation energy of hydrated formaldehyde and hydrated phenol. In all cases, three-body effects improved the excitation energy by the one- and two-body FMO methods with small computational cost, and the excitation energy approached more closely the full calculation value. The results also show that the three-body effects were relatively large and cannot be neglected.
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