Titel
Phase stability of the ice XVII-based CO2 chiral hydrate from molecular dynamics simulations
Autor*in
Abstract
We computed the phase diagram of CO2 hydrates at high pressure (HP), from 0.3 to 20 kbar, by means of molecular dynamics simulations. The two CO2 hydrates known to occur in this pressure range are the cubic structure I (sI) clathrate and the HP hydrate, whose water framework is the recently discovered ice XVII. We investigated the stability of both hydrates upon heating (melting) as well as the phase changes upon compression. The CO2-filled ice XVII is found to be more stable than the sI clathrate and than the mixture of ice VI and dry ice at pressure values ranging from 6 to 18 kbar and in a wide temperature range, although a phenomenological correction suggests that the stability should more realistically range from 6.5 to 13.5 kbar. Our simulation results support the current hypothesis that the HP hydrate is stable at temperatures above the melting curve of ice VI.
Stichwort
Crystalline solidsMolecular dynamicsWater modelPolymorphismComplex solidsPhase transitionsOrganic compounds
Objekt-Typ
Sprache
Englisch [eng]
Persistent identifier
Erschienen in
Titel
The Journal of Chemical Physics
Band
151
Ausgabe
10
ISSN
0021-9606
Erscheinungsdatum
2019
Publication
AIP Publishing
Erscheinungsdatum
12.09.2019
Zugänglichkeit
Rechte
Rechteangabe
© 2019 Author(s)
Universität Wien | Universitätsring 1 | 1010 Wien | T
+43-1-4277-0