Molecular Modeling of the Structure and Dynamics of the Interlayer Species of ZnAlCl Layered Double Hydroxide

Abstract

Molecular dynamics simulations of the ZnAl layered double hydroxide containing interlayer chloride anions have been performed in the NpT and Np(zz)T statistical ensembles for metal Zn/Al ratios of 2 and 3. We have monitored the interlayer spacing as a function of the number of intercalated water molecules for each statistical ensemble. We have studied how these profiles are affected by the method of calculation of the charges of the hydroxide layer atoms. Diffusion coefficients of the interlayer water molecules have been calculated for different Zn/Al ratios. The calculation of the chemical potential of the interlayer water molecules has been carried out for three amounts of interlayer water molecules. The calculation showed a qualitative agreement with the bulk water chemical potential within a range of interlayer water molecule contents.

DFT simulation of Mg/Al hydrotalcite with different intercalated anions: Periodic structure and solvating effects on the iodide/triiodide redox couple

“…Also organic anions, in some cases quite large, have been successfully intercalated, confirming the high flexibility of HT layered structure [27]. Because of the long range structural disorder and general low crystallinity of these materials, the X-ray structural determination is often supported by some kind of computational modeling, in most cases molecular dynamics (MD) simulations with classical force fields [10,11,26,[28][29][30][31][32][33]. In particular, some recent papers reported about MD calculations on HT intercalated with large organic molecules (e.g.…”

Molecular Dynamic Simulations of the Collision between Copper Ions, SF6 Molecules and a Polyethylene Surface: A Study of Decomposition Products and an Evaluation of the Self‐Diffusion Coefficients

“…We can see that the normalized velocity autocorrelation function oscillates around zero, meaning that the atoms of the polyethylene crystal have lost their correlation. This loss of memory of the atoms is obtained after more than 1 ps; this duration is more important than that obtained for a gas or a liquid 34, 35. Indeed, as the atoms are in the solid state, their movements are restricted within the crystal.…”

“…This loss of memory of the E. Duffour atoms is obtained after more than 1 ps; this duration is more important than that obtained for a gas or a liquid. [34,35] Indeed, as the atoms are in the solid state, their movements are restricted within the crystal. Finally, over all simulations, during the last 30 ps the self-diffusion coefficients of the remaining atoms that have not been emitted are in the range of 1 Â 10…”

Interlayer Structures and Dynamics of Arsenate and Arsenite Intercalated Layered Double Hydroxides: A First Principles Study

“…Part of the magnesium was replaced by aluminum to reach Mg/Al ratios of 2:1, 3:1, and 4:1. The isomorphic substitutions of Al for Mg in the octahedral sheets followed Loewenstein's rule [51,61] at relatively low layer charge densities (with a Mg/Al ratio of 3:1 or 4:1), that is, no substitution sites were adjacent, while at a Mg/Al ratio of 2:1, there were two neighboring substitution sites because the periodic boundary conditions did not allow all the trivalent cations to satisfy the cation avoidance rule, and some studies [50] have proven that a few adjacent substitution sites will not affect the overall structures and dynamics properties of LDHs. Considering the limits of computational power, we modified the original model with three octahedral sheets to two sheets, which consists of 4 × 4 × 2 M-OH octahedra.…”

“…Molecular simulations are very useful for exploring microscopic interlayer properties of layered materials [48]. Several molecular dynamics (MD) simulations of LDHs have been reported [46,[49][50][51][52][53]. For example, Kai et al [51] and Kumar et al [49] focused on the structures and energetics of LDHs.…”