International Centre for Theoretical Physics

Debashree Ghosh discusses quantum-chemistry approaches for strongly correlated polyaromatic hydrocarbons, including acenes and carotenoids. The talk examines why large valence active spaces are needed to describe optical properties and singlet–triplet gaps, and how density-matrix renormalization-group methods address these systems. Changes in molecular topology and odd-membered rings are connected to spin frustration and optical behaviour. The seminar also covers neural-network configuration interaction, connections between artificial neural networks and matrix-product-state wavefunctions, and restricted-Boltzmann-machine approaches to quantum wavefunctions. Applications include singlet fission and multiexcitonic phenomena. The hybrid event takes place in ICTP’s Euler Lecture Hall and online; the official event page provides the registration link.