B3LYP Periodic Study of the Physicochemical Properties of the Nonpolar (010) Mg-Pure and Fe-Containing Olivine Surfaces

Abstract

B3LYP periodic simulations have been carried out to study some physico-chemical properties of the bulk structures and the corresponding non-polar (010) surfaces of Mgpure and Fe-containing olivine systems; i.e, Mg2SiO4 (Fo) and Mg1.5Fe0.5SiO4 (Fo75). A detailed structural analysis of the (010) In contrast, the IR spectra of the surfaces are shifted to upper values and exhibit more bands compared to the corresponding bulk systems due to the shorter metal-O distances given in the coordinatively unsaturated metals and to symmetry reduction which brings non-equivalent motions between the outermost and the internal modes, respectively.

Interstellar H adsorption and H2formation on the crystalline (010) forsterite surface: a B3LYP-D2* periodic study

“…The resulting surface model contains 56 atoms per unit cell and has a thickness in the [010] cut direction, after geometry relaxation, close to the original b value (10.254 Å) 28 of the bulk unit cell from which the slab has been derived. A very recent work of us 28 presents an exhaustive discussion on the reconstruction effects, structural parameters and physico-chemical properties of this surface. Here, it is worth to highlight that this surface model is terminated by under- Computational Details.…”

“…36 The activated complex structures corresponding to the TS have been checked by ensuring that only one imaginary frequency resulted by the Hessian matrix Pople basis set); and (8s)-(511sp)-(1d) for the remaining Mg atoms. 28 For all calculations, a TZP basis set from the Ahlrichs and coworkers 37 has been used for the H atoms.…”

First‐principle modelling of forsterite surface properties: Accuracy of methods and basis sets

“…In recent years, a number of papers have appeared, tackling the complex task of developing models able to provide a reliable description of the atomic details of this mineral interface . Most of these studies focus on the interaction of hydrogen, water, or carbon dioxide with the (010) surface of forsterite (where both M sites are occupied by magnesium) as modeled either with interatomic potentials, or with first‐principle methods based on the density functional theory (DFT) .…”

“…[16,17] In recent years, a number of papers have appeared, tackling the complex task of developing models able to provide a reli-able description of the atomic details of this mineral interface. [18][19][20][21][22][23][24][25][26][27][28][29][30][31] Most of these studies focus on the interaction of hydrogen, water, or carbon dioxide with the (010) surface of forsterite (where both M sites are occupied by magnesium) as modeled either with interatomic potentials, [19,24] or with firstprinciple methods based on the density functional theory (DFT). [25,27,30,31] Of the latter, one presents a study on the adsorption of H 2 molecules on the (010) surface of forsterite performed at the hybrid meta-generalized gradient approximation (GGA) level of theory, though structures were optimized using interatomic potentials [27] ; four deal with the adsorption of either water molecules or H atoms and H 2 molecules on the same surface, simulated at the GGA [25,28,31] and B3LYP-D* [30] levels.…”

Interstellar Dust Analogues: Structure, Survivability and Physical Processes

“…See Fig 5.2. Extracted from All these positive identifications impel us to test the reactions 5.1 and 5.2 on top of the (010) surface of the above mentioned material, a surface extensively validated in previous works by the group of Dr. Rimola (Navarro-Ruiz et al, 2014b;Navarro-Ruiz et al, 2014a;Navarro-Ruiz et al, 2015) and the most stable forsterite surface (Goumans et al, 2009;Navarro-Ruiz et al, 2014a) . We expect our results to provide an atomistic scale interpretation of the formation of the initial stages of a water ice mantle (hereafter proto-ice mantle) in cold regions with enough density of energetic particles to maintain oxygen in its atomic form, at the boundary between diffuse and dense molecular clouds, sometimes referred as "translucent clouds" .…”