Researchers from the University of Pisa, including Matteo Rinaldi, Chiara Sepali, Alicia Marie Kirk, Claudio Amovilli, and Chiara Cappelli, have developed a new computational method to better understand how solvents interact with and influence the electronic states of dissolved substances. This research, published in the Journal of Chemical Physics, could have significant implications for the energy industry, particularly in areas like photovoltaics and catalysis.
The team’s method, called DMRG/FQ, combines two existing techniques: the Density Matrix Renormalization Group (DMRG) and a polarizable fluctuating-charge (FQ) force field. DMRG is particularly good at handling systems with strong static correlations, while the FQ model provides a physically grounded representation of how solvents polarize, or change their electronic distribution, in response to a dissolved substance.
In the energy industry, understanding these interactions is crucial. For instance, in photovoltaics, the efficiency of solar cells can be influenced by the solvent used in the fabrication process. Similarly, in catalysis, the solvent can affect the reaction rates and pathways. By providing a more accurate picture of these interactions, the DMRG/FQ method could help researchers design more efficient solar cells and catalysts.
The researchers tested their method on several solvated systems, using extensive molecular dynamics sampling. They found that their method yielded reliable excitation energies and solvatochromic shifts, which are changes in the absorption or emission spectra of a substance due to the solvent. Moreover, their results agreed closely with available experimental data, highlighting the importance of mutual polarization for capturing specific solute-solvent interactions, particularly in systems where hydrogen bonding or directional interactions play a dominant role.
While the DMRG/FQ method is still a computational tool and not a direct energy technology, its potential to provide deeper insights into solvent-substance interactions could lead to significant advancements in the energy sector. By helping researchers better understand and optimize these interactions, the method could contribute to the development of more efficient and sustainable energy technologies.
This article is based on research available at arXiv.

