Mandle, R.J., Sebastián, N., Martinez-Perdiguero, J. et al. On the molecular origins of the ferroelectric splay nematic phase. Nat Commun 12, 4962 (2021). https://doi.org/10.1038/s41467-021-25231-0

The members of the Department of Complex Matter at the Jožef Stefan Institute Alenka Mertelj and Nerea Sebastián, together with Richard J. Mandle for the University of Leeds and Josu Martinez-Perdiguero from the University of the Basque Country have recently published an article in Nature Communications with the title “On the molecular origins of the splay nematic phase”. Polar nematic phases have been long-time predicted, but have only been experimentally realized recently. In this paper, the authors compare, both experimentally and by means of molecular dynamic simulations, two materials with similar chemical structure and demonstrate that a subtle molecular change enables denser packing when they exhibit polar order. Such reduction of the excluded volume lies in the origin of the polar nematic phase. This contribution shows how MD simulations can be used for molecular design, by predicting and identifying candidate materials for the polar or its precursor nematic phases.

Raziskovalki Nerea Sebastián in Alenka Mertelj z Odseka za kompleksne snovi sta v sodelovanju z Richardom J. Mandlom z Univerze v Leedsu in Josujem Martinez-Perdiguerom z Univerze v Baskiji v reviji Nature Communication poročali o raziskavi molekularnega izvora pahljačaste feroelektrične faze (https://www.nature.com/articles/s41467-021-25231-0). Čeprav so polarno nematično fazo teoretično napovedali že dolgo nazaj, je do njene realizacije prišlo šele pred kratkim. V tem delu avtorji eksperimentalno in s simulacijami molekulske dinamike primerjajo dva materiala z zelo podobno kemijsko strukturo in pokažejo, da že zelo majhna sprememba strukture molekule omogoči gostejše zlaganje molekul, kadar so v polarni fazi. Zmanjšanje izključitvenega volumna je tako vzrok za nastanek polarne faze. V tem prispevku avtorji tudi demonstrirajo, da lahko simulacije molekulske dinamike uporabimo za napovedovanje in identifikacijo materialov, ki so potencialni kandidati za feroelektrično nematično fazo.