Berlin 2015 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 58: Computational Physics of Soft Matter II
CPP 58.6: Vortrag
Mittwoch, 18. März 2015, 17:15–17:30, PC 203
Proton disorder in cubic ice: Effect on the electronic and optical properties — Viviana Garbuio1, Olivia Pulci1, Michele Cascella2, Igor Kupchak3, and •Ari Paavo Seitsonen4,5 — 1MIFP, ETSF, Dipartimento di Fisica, Università di Roma Tor Vergata, Italy — 2Department of Chemistry and Centre for Theoretical and Computational Chemistry, University of Oslo, Norway — 3MIFP, V. Lashkarev Institute of Semiconductor Physics of National Academy of Sciences of Ukraine, Kiev — 4Institut für Chemie, Universität Zürich, Switzerland — 5Département de Chimie, École Normale Supérieure, Paris, France
The proton disorder in ice has a key role in several properties such as the growth mode, thermo- dynamical properties and ferroelectricity. While structural phase transitions from proton disordered to proton ordered ices have been extensively studied, much less is known about their electronic and optical properties. Here, we present ab-initio many body perturbation theory based calculations of the electronic and optical properties of cubic ice at different levels of proton disorder. We compare our results with liquid water, as an example of fully (proton and oxygen) disordered system. We find that, by increasing the disorder, a shrinking of the electronic gap occurs. Simultaneously, the excitonic binding energy decreases, so that the final optical gaps result to be almost independent on the degree of disorder. We explain these findings as an interplay between the local dipolar disorder and the electronic correlation.