Title:	Allocation for theoretical chemistry research at LiU
DNr:	LiU-compute-2022-16
Project Type:	LiU Compute
Principal Investigator:	Bo Durbeej <bo.durbeej@liu.se>
Affiliation:	Linköpings universitet
Duration:	2022-05-01 – 2025-05-01
Classification:	10407
Homepage:	https://liu.se/forskning/teoretisk-kemi
Keywords:

Abstract

This project is a continuation of the project LiU-2017-00089-11 on the Sigma system, which ends on 2022-05-01 and supports theoretical chemistry research at LiU. The present proposal is submitted with the hope to maintain this allocation, which has been indispensable for the research in this field at LiU. Broadly, the current and planned theoretical chemistry research at LiU is carried out along two main lines - computational photochemistry (research led by Bo Durbeej) and computational organic electronics and supramolecular chemistry (research led by Mathieu Linares) - and is supported by several external sources: VR, SeRC, Olle Engkvists Stiftelse, ÅForsk and Carl Tryggers Stiftelse. The planned research in computational photochemistry has three main objectives, all of which rely heavily on continued access to state-of-the-art HPC resources. The first is to design more efficient and useful molecular photoswitches and light-driven molecular motors for applications in solar-energy storage and nanotechnology, respectively. To this end, we perform quantum chemical calculations to design switches/motors with favorable light-absorption characteristics and carry out semi-classical, non-adiabatic molecular dynamics (NAMD) simulations to predict the quantum yields of the photochemical reactions that power the switches/motors. The second objective, in turn, is to find strategies for strengthening the fluorescence of phytochrome proteins and making them emit light in the near-infrared regime, which would enable many new applications in fluorescence microscopy-based bioimaging. To reach this goal, we first run classical MD simulations to generate structures of phytochromes that incorporate amino-acid mutations believed to red-shift the fluorescence and increase the associated quantum yield. Based on the resulting structures, we then test these predictions by performing hybrid quantum mechanics/molecular mechanics (QM/MM) calculations, wherein the light-emitting chromophore is treated quantum mechanically and the surrounding protein matrix is described with a classical force field. The third objective, finally, is of methodological character and is aimed at developing new procedures for more reliable and less resource-demanding modelling in photochemistry. The planned research in computational organic electronics and supramolecular chemistry also relies heavily on continued access to state-of-the-art HPC resources. Within this programme, one key objective is to gain a better understanding of charge dynamics in organic solar cells, so as to identify organic materials that allow such devices to transform solar energy into electricity as efficiently as possible. To this end, we model charge dynamics in organic materials by means of kinetic Monte Carlo (KMC) simulations, with the aim to uncover both intrinsic structural and electronic material features and material combinations that are favorable in this regard. Another key objective is to understand the self-assembly of supramolecular structures of biological relevance, and particularly the relationship between chirality at the single-molecule level and helicity at the supramolecular level. This relationship is studied by modelling the self-assembly of chiral molecules using a combination of classical MD simulations (providing structural insight) and quantum chemical calculations (providing insight through computed circular dichroism spectra).