Related papers: Cage occupancies in nitrogen clathrate hydrates fr…
Thermodynamic stability of N$_2$ clathrate hydrates in the sI and sII structures is investigated using density functional theory with several exchange-correlation functionals, explicitly accounting for composition (cage occupancies) and…
An accurate knowledge of cage occupancy of methane is central for understanding the physical-chemical properties of gas hydrates, the actual inventory of natural gas in hydrate deposits and the description of gas exchange processes. Here we…
Structure, stability and reactivity of clathrate hydrates with or without hydrogen encapsulation are studied using standard density functional calculations. Conceptual density functional theory based reactivity descriptors and the…
We introduce a simulation technique to compute the free energy difference between two hydrate structures of different stoichiometry connected to a reservoir of gas molecules at a prescribed pressure. The method permits the determination of…
Kinetic Monte-Carlo simulation is applied to study the partial oxidation of methane over a nickel catalyst. Based on the Langmuir-Hinshelwood mechanism, the kinetic behavior of this reaction is analyzed and the results are compared with…
Zr oxides and oxynitrides are promising candidates to replace precious metal cathodes in polymer electrolyte fuel cells. Oxygen reduction reaction activity in this class of materials has been correlated with the amount of oxygen vacancies,…
Methane clathrate hydrates, particularly those with an sI structure, are significant due to their potential as energy resources and their impact on gas pipelines. In this study, a two-dimensional (2D) lattice-gas model is employed to…
We present ab initio results at the density functional theory level for the energetics and kinetics of H_2 and CH_4 in the SI clathrate hydrate. Our results complement a recent article by some of the authors [G. Roman-Perez et al., Phys.…
The formation of H2 in the interstellar medium proceeds on the surfaces of silicate or carbonaceous particles. To get a deeper insight of its formation on the latter substrate, this letter focuses on H2 desorption from graphite (0001) in…
This work gives a van't Hoff law expression of Langmuir constants of different species for determining their occupancy in the nanocavities of clathrate hydrates. The van't Hoff law's parameters are derived from a fit with Langmuir constants…
Multiphase Gibbs ensemble Monte Carlo simulations were carried out to compute the free energy of swelling for Na-montmorillonite and Na-beidellite interacting with CO2 and H2O at pressure and temperature conditions relevant for geological…
Carbon dioxide (CO2) storage reservoirs commonly exhibit sedimentary architecture that reflects fluvial deposition. The heterogeneity in petrophysical properties arising from this architecture influences the dynamics of injected CO2. We…
We present, in this work, our preliminary results of a systematic theoretical study of the adsorption of N over As-terminated GaAs (100) (2$\times$1) surfaces. We analyzed the changes in the bond-lenghts, bond-angles and the energetics…
We determine thermodynamic stability conditions in terms of Helmholtz and Gibbs energies for sI clathrate hydrates with CH$_4$ and CO$_2$ at 278 K. Helmholtz energies are relevant for processing from porous rocks (constant volume), while…
The study of the interaction potential between static charges within Monte-Carlo simulation of graphene is carried out. The numerical simulations are performed in the effective lattice field theory with noncompact $3 + 1$-dimensional…
The separation of carbon dioxide CO$_2$ from nitrogen gas (N$_2$), the main component of flue gas, has become an emerging action to mitigate climate change. Feasible and efficient approaches to exploring the separation properties of…
A binary lattice gas model that allows for multiple occupancy of lattice sites, inspired by recent coarse-grained descriptions of solutions of interacting polymers, is investigated by combining the steepest descent approximation with an…
Unbiased stochastic sampling of the one- and two-body reduced density matrices is achieved in full configuration interaction quantum Monte Carlo with the introduction of a second, "replica" ensemble of walkers, whose population evolves in…
The monolayer adsorption process of interacting binary mixtures of species $A$ and $B$ on square lattices is studied through grand canonical Monte Carlo simulation in the framework of the lattice-gas model. Four different energies have been…
We report results from grand-canonical Monte Carlo simulations of methane and carbon dioxide adsorption in structure sI gas hydrates. Simulations of pure component systems show that all methane sites are equivalent, while carbon dioxide…