Simulating UV/vis and circular dichroism spectra for large-scale molecular systems under pressure

• Applicant: Dr. Manuel Brand
• Subject Area: Theoretical Chemistry: Electronic Structure, Dynamics, Simulation ; Theoretical Chemistry: Molecules, Materials, Surfaces
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 525879088

Materials exhibiting pressure-induced changes in physical or spectroscopic properties give rise to a manifold of useful applications. The theoretical studies that are needed to fully unravel the underlying phenomena at the molecular scale lag behind the experimental advancements in the field. While out of reach previously, a foundation for the former was laid recently with the development of GOSTSHYP, as the first pressure model that explicitly incorporates the change in the electron density introduced by the applied pressure. The aim of the research work proposed herein is to derive and implement an extension to this formalism enabling spectroscopy simulations by means of linear response theory. The implementation work will be carried out in the VeloxChem program code, developed for efficient utilization of high-performance computing resources. Subsequently, a series of calculations involving benzene molecules and clusters of various sizes should demonstrate the ability of the implemented methodology to capture experimentally observed phenomena, as well as elucidate the interplay between intra- and intermolecular effects on pressure-induced property changes. Lastly, in a large-scale study on helicene molecules the pressure-dependency of, e.g., circular dichroism as important property and its correlation with experimentally observed structural changes will be investigated. Overall, the provided implementation and obtained insights are expected to hold the potential to steer future developments of piezochromatic materials of desired properties.

• DFG Programme: WBP Position