Delving into guest-free and He-filled sI and sII clathrate hydrates: a first-principles computational study

Abstract

The dynamics of the formation of a specific clathrate hydrate as well as its thermodynamic transitions depend on the interactions between the trapped molecules and the host water lattice. The...

Computational investigations of stable multiple-cage-occupancy He clathrate-like hydrostructures

“…55,56 Therefore, given the great interest aroused by the aforementioned helium clathrate hydrates, in this work we share new insights into these inclusion compounds as a part of our line of research. [57][58][59] In previous studies, we have benchmarked the performance of different DFT functionals through a validation protocol in comparison with well-converged wavefunction (WF)-based reference data, and we have identified the bestperforming functionals in describing such weak guest-host interactions, together with the appropriate dispersion correction schemes. Now we intend to go one step further by analyzing the effect of multiple cage occupancy in the sII clathrate hydrate in terms of structural, energetic and thermochemical properties.…”

Analysing the stability of He-filled hydrates: how many He atoms fit in the sII crystal?

“…The PW86PBE (with and without dispersion schemes) results related to sII and He (1/1) @sII structures are extracted from ref. 55. Solid lines correspond to the MEOS fits.…”

“…Similar discussions about cage occupancy in clathrate hydrates with other guest species have been found in the literature. 38,[48][49][50][51][52] Therefore, in tune with our earlier research, [53][54][55] we aim to study the multiple cage occupancy effects in the crystalline systems through periodic DFT/DFT-D calculations. Thus, we can make a more direct comparison with the experimental outcomes, elucidating which He-filled configuration is more likely to form.…”

Confining CO2 inside sI clathrate‐hydrates: The impact of the CO2–water interaction on quantized dynamics

“…Clathrate hydrates are crystalline water‐based inclusion compounds with gas molecules trapped in the cavities formed by the ice–water networks. They have been extensively studied due to their technological applications 1–35 . For example, the CO 2 clathrate hydrates are of interest driven by their potential use in CO 2 gas capture and storage from the Earth's atmosphere, and control climate change, 36–38 while in an astrophysical context their formation and presence could influence the composition and stability of planetary ices and comets 39–41 .…”