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The problem of computing accurately the long-range Coulomb interactions in physical systems is investigated focusing mainly on the atomistic simulation of fluids sorbed in porous solids. Several articles involving theory and computation of long-range interactions in charged systems are reviewed, in order to explore the possibility of adapting or developing methodology in the field of computer simulation of sorbate molecules inside nanostructures modeled through a three-dimensional (crystal frameworks), two-dimensional (slit-shaped pores), or one-dimensional (cylindrical pores) replication of their unit cell. For this reason we digitally reconstruct selected paradigms of three-dimensional microporous structures which exhibit different spatial periodicities such as the zeolite crystals of MFI and FAU type, graphitic slit-shaped pores, and single-wall carbon nanotubes in order to study the sorption of CO2, N2, and H2 via grand canonical Monte Carlo simulation; the predicted data are compared with experimental measurements found elsewhere. Suitable technical adjustments to the use of conventional Ewald technique, whenever it is possible, prove to be effective in the computation of electrostatic field of all the categories studied in this work. [ABSTRACT FROM AUTHOR]

Atomistic computer simulation was employed to understand sorption thermodynamics and mass transport study of hydrogen and its isotope deuterium sorbed in NaX zeolite at 77 and 100 K. The results obtained provide insight into the dependence of sorption thermodynamics and sorbate dynamics on the sorbed phase concentration.

This study describes the development and application of a new computational methodology for calculating the self-diffusivity of sorbate molecules strongly confined within shape-selective nanoporous materials. An umbrella sampling strategy, employing repulsive walls to confine the sorbate within specific regions of the pore space, is invoked to extract free energy profiles with respect to the sorbate degrees of freedom. Based on these profiles, it is shown how the multidimensional problem of translational diffusion of benzene in flexible silicalite-1 can be reduced first to a six-dimensional problem, then to a three-dimensional (3D) problem and finally, to a 1D problem. A 3D free energy distribution is accumulated as a function of the benzene centre of mass position and ultimately reduced to a set of 1D profiles for the benzene centre of mass along the pore axes. From these profiles, the rate constants for jumps executed by benzene between sorption sites are calculated using transition state theory; from the latter rate constants, the low-occupancy self-diffusivity is obtained using the MESoRReD method [Kolokathis PD, Theodorou DN. On solving the master equation in spatially periodic systems. J Chem Phys. 2012;137:034112]. The activation energy for diffusion and preferred orientations in the various sorption states in silicalite are in very favourable agreement with available experimental measurements. [ABSTRACT FROM PUBLISHER]