How Dispersion Interactions at the Excited State Can Tune Photochromism of Embedded Chromophores
We present QM/MMPol-cLR<sup>3</sup>, a polarizable embedding quantum mechanics/molecular mechanics (QM/MM) framework that includes explicit, state-specific dispersion terms. This method enables a rigorous treatment of dispersion on top of electrostatic and induction effects in ground- an...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/225923 |
| Acceso en línea: | https://hdl.handle.net/2445/225923 |
| Access Level: | acceso embargado |
| Palabra clave: | Col·loides Polaritat Dissolvents Colloids Polarity Solvents |
| Sumario: | We present QM/MMPol-cLR<sup>3</sup>, a polarizable embedding quantum mechanics/molecular mechanics (QM/MM) framework that includes explicit, state-specific dispersion terms. This method enables a rigorous treatment of dispersion on top of electrostatic and induction effects in ground- and excited-state calculations. Using QM/MMPol-cLR<sup>3</sup>, we show that dispersion interactions control excited-state solvatochromism through two distinct mechanisms. In azulene, opposite shifts of the L<sub>a</sub> and L<sub>b</sub> states arise from state-specific dispersion linked to changes in excited-state polarizability. In bacteriochlorophyll a, dispersion instead stems from the interplay between polarizability changes and transition-dipole-driven response, governing the <em>Q</em><sub><em>y</em></sub> and <em>Q</em><sub><em>x</em></sub> shifts. Finally, application to the LH2 complex reveals pigment-dependent dispersion shifts between the B800 and B850 rings, impacting the excitation-energy transfer. These results establish dispersion as an essential, nonempirical component for predictive excited-state simulations in complex environments. |
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