Influence of combining rules on the cavity occupancy of clathrate hydrates using van der Waals–Platteeuw-theory-based modelling

2014 ◽  
Vol 92 (12) ◽  
pp. 2992-3007 ◽  
Author(s):  
Ioannis N. Tsimpanogiannis ◽  
Nikolaos I. Diamantonis ◽  
Ioannis G. Economou ◽  
Nikolaos I. Papadimitriou ◽  
Athanassios K. Stubos
Keyword(s):  
Van Der Waals ◽  
Clathrate Hydrates

Molecular dynamics simulation of halogen bonding in Cl2, BrCl, and mixed Cl2/Br2 clathrate hydrates

2015 ◽  
Vol 93 (8) ◽  
pp. 864-873 ◽  
Author(s):  
Hana Dureckova ◽  
Tom K. Woo ◽  
Saman Alavi ◽  
John A. Ripmeester
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Van Der Waals ◽  
Halogen Bonding ◽  
Clathrate Hydrate ◽  
Clathrate Hydrates ◽  
Dynamics Simulation ◽  
Water Oxygen ◽  
Dynamics Simulations ◽  
Van Der Waals Radii

Clathrate hydrate phases of dihalogen molecules have properties that differ from those of other guest molecules of similar size. The water oxygen–chlorine distances in the structure I (sI) Cl2 hydrate are smaller than the sum of the van der Waals radii of oxygen and chlorine. Bromine hydrate forms a unique clathrate hydrate structure that is not seen in other guest substances. In mixed Cl2/Br2 structure I hydrate, the water oxygen–bromine distances are also smaller than the sum of the oxygen and bromine van der Waals radii. We previously studied the structure of three dihalogen clathrate hydrates using single crystal X-ray diffraction and described these structural features in terms of halogen bonding between the dihalogen and water molecules. In this work, we perform molecular dynamics simulations of cubic sI Cl2, mixed Cl2/Br2, and BrCl clathrate hydrate phases. We perform quantum chemical computations on the dihalogen molecules to determine the nature of σ-hole near the halogen atoms. We fit the electrostatic potential of the molecules to point charge models including dummy atoms that represent σ-holes adjacent to the halogen molecules. Molecular dynamics simulations are used to determine the lattice constants, radial distribution functions, and guest dynamics in these phases. We determine the effect of guest size and difference in halogen bonding on the properties of the clathrate hydrate phase. Simulations for the Cl2, BrCl, and mixed Cl2/Br2 hydrates are performed with small cages of the sI clathrate hydrate phases completely full or filled with experimental occupancies with Cl2 guests.

Sixty Years of the van der Waals and Platteeuw Model for Clathrate Hydrates—A Critical Review from Its Statistical Thermodynamic Basis to Its Extensions and Applications

2020 ◽  
Vol 120 (24) ◽  
pp. 13349-13381
Author(s):  
Fernando de Azevedo Medeiros ◽  
Iuri Soter Viana Segtovich ◽  
Frederico Wanderley Tavares ◽  
Amadeu K. Sum
Keyword(s):  
Critical Review ◽  
Van Der Waals ◽  
Clathrate Hydrates ◽  
Statistical Thermodynamic ◽  
Thermodynamic Basis
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