G5 Article dissertation
Data-driven spectrum interpretation in the liquid phase
Authors: Eronen, Eemeli
Publishing place: Turku
Publication year: 2026
Series title: Annales Universitatis Turkuensis AI
Number in series: 760
ISBN: 978-952-02-0676-5
eISBN: 978-952-02-0677-2
ISSN: 0082-7002
eISSN: 2343-3175
Publication's open availability at the time of reporting: Open Access
Publication channel's open availability : Open Access publication channel
Web address : https://urn.fi/URN:ISBN:978-952-02-0677-2
Interpreting liquid-phase electronic spectra is challenging due to the complex interplay of atomic motion and intermolecular interactions. These effects create a wide distribution of local atomistic environments, each of which can yield a signifcantly different spectrum. Because experiments only capture ensemble averages, any observed spectral change refects a latent shift in the underlying distribution of spectrally relevant structural features. In this thesis, I introduce a data-driven framework for disentangling the structure–spectrum relationship by adapting the recently proposed emulator-based component analysis. Applied to extensive simulated datasets, this spectrum-variance-driven dimensionality reduction method transforms the high-dimensional problem into a low-dimensional form, uncovering structural trends behind spectral changes. Across the studied cases, most of the spectral variation is explained by a small fraction of structural variance, represented by only a few latent structural degrees of freedom. This emerging pattern may indicate a general principle in spectroscopy of liquids.