arXiv subjects

Albert Rimola

Publications and source records attributed to Albert Rimola.

At least 19 recordsLinked to original sources

arXiv2026

Nudged Elastic Band Method in the CRYSTAL code. Theory and Applications

The nudged elastic band (NEB) method is a widely used algorithm for determining minimum energy paths and transition states in chemical reactions and phase transitions. In this work, we present the implementation of different NEB algorithm schemes in the CRYSTAL code, a quantum mechanical ab initio program for the calculation of electronic properties of condensed matter systems, based on Hartree-Fock and density functional theory. The use of a set of localized Gaussian-type functions to expand the wavefunction permits a very efficient evaluation of the exact exchange series for the hybrid exchange-correlation functionals. Therefore, our implementation allows an accurate characterization of transition states in both molecular and condensed phase systems, at the hybrid functional level of theory. The theoretical framework, including the force projection scheme, tangent estimation, optimization strategies, as well as the extensions of the method with climbing image and variable spring constant variants, is recalled. Then, the NEB algorithm is validated through a series of benchmark tests: two molecular reactions (a collinear proton transfer process and the keto-enol tautomerization in formamide) and a proton exchange process in a periodic chabazite zeolite. Our results are in excellent agreement with experimental and previous theoretical data, confirming the accuracy and applicability of the implementation. This work opens the possibility for future studies of complex reactive processes on extended periodic systems, using hybrid functionals.

cond-mat.mtrl-sci↗

arXiv2026

When Two Worlds Collide: How Collisions Between Silicate and Carbonaceous Nanograins can Drive Complex Chemistry

Our overall objective is to determine how collision velocity governs the interactions between silicate and carbonaceous nanograins. We aim to: i) identify collisional regimes capable of producing mixed silicate-carbonaceous grains and/or chemically complex molecular species, and ii) quantify fragmentation threshold velocities related to dust destruction. We performed molecular dynamics simulations employing a machine-learning force field to model head-on collisions between silicate and carbonaceous nanograins of comparable masses. Collision velocities span 1 - 11 km/sec. For all collisions, we tracked the extent of grain-grain mixing and the formation of molecular fragments. We identified four velocity regimes: 1) <1.5 km/sec, where grains bounce off one another, 2) 1.5-3.5 km/sec, where sticking between the grains starts to occur, 3) 3.5-7.5 km/sec, where grains tend to aggregate and form inter-grain chemical bonds, yielding stable mixed grains, and 4) >7.5 km/sec, where fragmentation dominates. The latter regime produces CO as the main product, along with hydrocarbons, complex organic molecules, molecular silicates, and mixed carbonaceous-silicate clusters. The fragmentation threshold velocity for these collisions is approximately 7.5 km/sec. We show that collision velocities govern both the physical and chemical outcomes of silicate-carbonaceous nanograin interactions. In the fragmentation regime, collisions provide a viable pathway for generating mixed grains and a wide range of molecular species, many of which have been observationally detected. Here, we provide a simple credible mechanism linking the physics of grain processing with observed complex interstellar chemistry.

astro-ph.GA↗

arXiv2026

Chemical Complexity in the Early Stages of Star Formation in the SKAO Era

About 350 molecules have been identified in the interstellar medium (ISM), including complex molecules relevant to prebiotic chemistry. A remarkable level of molecular diversity has been observed from the earliest stages of star formation, providing the initial chemical inventory inherited by planetary systems. Radio observations have played a pivotal role in these discoveries, starting with the identification of the first polyatomic molecule, $\text{NH}_3$ (Cheung et al. 1968). (Sub-)millimeter observations have revealed complex organic molecules of prebiotic relevance, including formamide ($\text{NH}_2\text{CHO}$), glycolaldehyde ($\text{CH}_2\text{OHCHO}$), and even urea ($(\text{NH}_2)_2\text{CO}$), and hydroxylamine ($\text{NH}_2\text{OH}$), which are possible precursors of RNA nucleotides (Ceccarelli et al. 2023; Jim\'enez-Serra et al. 2020). However, in dense protostellar regions, dust opacity hampers the detection of molecular emission. Additionally, large molecules and those containing heavy atoms, which have rotational transitions at lower frequencies, often remain inaccessible to current instruments. The Square Kilometre Array Observatory (SKAO) will provide an unprecedented combination of sensitivity and angular resolution at radio wavelengths. This will allow for the detection of prebiotic species and offer new insights into the chemical pathways that shape emerging planetary systems (Jim\'enez-Serra et al. 2022). This chapter details the scientific questions and advancements that the SKAO, and more specifically, SKA-Mid equipped with the Band 5 receivers, will pursue in the field of astrochemistry, focusing on the chemical complexity in both high-mass and solar-type star-forming regions.

astro-ph.SR↗

arXiv2026

High-resolution mid-IR spectroscopy of SVS 13-A with EXES/SOFIA: The surprisingly high CH$_3$OH/H$_2$O ratio in the planet-forming zone of a solar mass protostar

Water and methanol are key components of interstellar ices and gas in star- and planet-forming regions, but direct observations of water in low-mass protostars are challenging due to atmospheric absorption. We present high-resolution (R = 70,500) mid-infrared spectroscopy of the Class I protostar SVS13-A with EXES on board SOFIA at 26 $μ$m, targeting both H$_2$O and CH$_3$OH absorption lines. Several lines of each species are detected, tracing warm gas with rotational temperatures of $\sim$140--170 K. Remarkably, the methanol column density is a factor of $\sim$4 higher than that of water, well above typical interstellar ice ratios ($<$10\%). Comparison with previous millimeter observations indicates that absorption and emission probe distinct regions, with the mid-IR lines likely tracing cooler gas along the line of sight. The surprising observed CH$_3$OH/H$_2$O ratio may reflect selective sublimation due to the distribution of binding energies or ice stratification in the inner envelope. These observations probe the inner regions of the protostar, where planets are expected to form and inherit the chemical composition of their natal environment, providing a direct link between ice sublimation and gas-phase chemistry. Our results represent the first high-spectral-resolution mid-infrared view of both water and methanol toward a low-mass protostar, offering a unique window into the chemical composition of the innermost envelope and planet-forming region, and highlighting the diagnostic power of high-resolution mid-infrared spectroscopy to uncover hidden chemical layers and the ice-to-gas transition in embedded protostars.

astro-ph.SR↗

arXiv2025

FAUST XXIX. OCS line emission: a new method for measuring the luminosity of embedded protostars in binary systems

The luminosity of embedded protostars is commonly measured via observations of the dust continuum spectral energy distribution from millimetre to infrared wavelengths. However, this method cannot be applied to embedded protostars in binary or multiple systems, where their components are usually unresolved over this extended wavelength range. We propose a new method, based on the idea that a molecule formed (mainly) on the grain surfaces only emits lines in the region where it thermally sublimates from the grain mantles, heated by the photons emitted by the embedded source. In this respect, carbonyl sulfide (OCS) is an optimal molecule, because of its low binding energy and rotational lines in the millimetre. We apply the method to the protobinary system NGC1333 IRAS4A, using ALMA high-spatial resolution ($\sim$50 au) observations of the OCS(19-18) line as part of the ALMA Large Program FAUST. We also present new quantum mechanics calculations of the OCS binding energy distribution, essential for the application of the method. We found that the two binary components, A1 and A2, have a comparable luminosity within the error bars, 7.5$\pm$2.5 and 7$\pm$1 L$_\odot$, respectively. We discuss the reliability of the estimated luminosities and the potential of this new method for measuring the luminosity of embedded protostars in binary and multiple systems.

astro-ph.SR↗

arXiv2025

Is cosmic dust porous?

There is a long-standing discussion in the astrophysical/astrochemical community as to the structure and morphology of dust grains in various astrophysical environments (e.g., interstellar clouds, protostellar envelopes, protoplanetary and debris disks, and the atmospheres of exoplanets). Typical grain models assume a compact dust core which becomes covered in a thick ice mantle in cold dense environments. In contrast, less compact cores are likely to exhibit porosity, leading to a pronounced increase in surface area with concomitant much thinner ice films and higher accessibility to the bare grain surface. Several laboratory experimental and theoretical studies have shown that this type of dust structure can have a marked effect on several physico-chemical processes, including adsorption, desorption, mobility, and reactivity of chemical species. Porous grains are thus thought to likely play a particularly important and wide-ranging astrochemical role. Herein, we clarify what is meant by porosity in relation to grains and grain agglomerates, assess the likely astrochemical effects of porosity and ask whether a fractal/porous structural/morphological description of dust grains is appropriate from an astronomical perspective. We provide evidence for high porosity from laboratory experiments and computational simulations of grains and their growth in various astrophysical environments. Finally, we assess the observational constraints and perspectives on cosmic dust porosity. Overall, our paper discusses the effects of including porosity in dust models and the need to use such models for future astrophysical, astrochemical and astrobiological studies involving surface or solid-state processes.

astro-ph.GA↗

arXiv2025

Formation of the glycine isomer glycolamide (NH$_2$C(O)CH$_2$OH) on the surfaces of interstellar ice grains: Insights from atomistic simulations

Syn-glycolamide, a glycine isomer, has recently been detected in the G+0.693-0.027 molecular cloud. Investigations on its formation in the interstellar medium could offer insights into synthetic routes leading to glycine in prebiotic environments. Quantum chemical simulations on glycolamide (NH$_2$C(O)CH$_2$OH) formation on interstellar ice mantles, mimicked by a water ice cluster model, are presented. Glycolamide synthesis has been here modeled considering a stepwise process: the coupling between formaldehyde (H$_2$CO) and the radical of formamide (NH$_2$CO$^{\bullet}$) occurs first, forming the glycolamide precursor NH$_2$C(O)CH$_2$O$^{\bullet}$, which is then hydrogenated to give anti-glycolamide. We hypothesize that anti-to-syn interconversion will occur in conjunction with glycolamide desorption from the ice surface. The reaction barrier for NH$_2$C(O)CH$_2$O$^{\bullet}$ formation varies from 9 to 26 kJ mol$^{-1}$, depending on surface binding sites. Kinetic studies indicate that this reaction step is feasible in environments with a $T > 35~\text{K}$, until desorption of the reactants. The hydrogenation step leading to anti-glycolamide presents almost no energy barrier due to the easy H atom diffusion towards the NH$_2$C(O)CH$_2$O$^{\bullet}$ intermediate. However, it competes with the extraction of an H atom from the formyl group of NH$_2$C(O)CH$_2$O$^{\bullet}$, which leads to formyl formamide, NH$_2$C(O)CHO, and H$_2$. Nonetheless, according to our results, anti-glycolamide formation is predicted to be the most favored reactive channel.

astro-ph.GA↗

arXiv2025

Atomistic insights on prebiotic phosphorylation of methanol from Schreibersite (Fe2NiP) corrosion: ab-initio computational study

The prebiotic history of phosphorus is a matter of debate in the scientific community: its origin, how it landed on Earth, the selective speciation of the phosphate, and its inclusion into the organic matrix are the main unsolved issues. In this regard, Schreibersite ((Fe,Ni)3P), a mineral present in iron meteorites, can play a fundamental role as a carrier of reactive P which, as a result of the weathering processes, produces oxygenated phosphorus compounds, even the phosphate among others. In the present paper, we studied the interaction of methanol (alone and mixed with water) with the Schreibersite surfaces throughout periodic density functional theory calculations at PBE level. The results indicate that Schreibersite promotes the deprotonation of methanol and water both from thermodynamic and kinetic points of view, thus enabling the first step towards corrosion. We have simulated advanced stages of the corrosion process up to the formation of the phosphate and the phosphorylated form of methanol (methyl phosphate), showing that the formation of both products is thermodynamically favoured, as well as its solubilization, which allows other water molecules to proceed with further corrosion of Schreibersite.

physics.chem-ph↗

arXiv2025

The prebiotic pathway from P-bearing iron meteorites to phosphates by DFT modeling

Among the biogenic macroelements, phosphorus is the one bringing the most fascinating and unsolved mysteries for what concern its prebiotic history. It possibly landed on Earth as a metal phosphide (Schreibersite, (Fe,Ni)3P), throughout the Heavy Meteor Bombardment during the Archean Era. Its subsequent corrosion by water led to P-oxygenated compounds, which is the subject of this kinetic computational study, thus complementing our previous thermodynamic characterization. The reaction was studied at periodic DFT level, simulating the water corrosion reaction on the reactive Fe2NiP Schreibersite (001)2 surface. Results show that the timescale of the reaction at 350 K is of few hours.

astro-ph.EP↗

arXiv2024

Unraveling the Interface Chemistry between HCN and Cosmic Silicates by the Interplay of Infrared Spectroscopy and Quantum Chemical Modeling

Understanding the interaction between hydrogen cyanide (HCN) and silicate surfaces is crucial for elucidating the prebiotic processes occurring on interstellar grain cores, as well as in cometary and meteoritic matrices. In this study, we characterized the adsorption features of HCN on crystalline forsterite (Mg2SiO4) surfaces, one of the most abundant cosmic silicates, by combining experimental infrared spectra at low temperatures (100-150 K) with periodic DFT simulations. Results showed the coexistence of both molecular and dissociative HCN adsorption complexes as a function of the considered forsterite crystalline face. Molecular adsorptions dominate on the most stable surfaces, while dissociative adsorptions occur predominantly on surfaces of lower stability, catalyzed by the enhanced Lewis acid-base behavior of surface-exposed Mg2+-O2- ion pairs. On the whole set of adsorption cases, harmonic frequency calculations were carried out and compared with the experimental infrared bands. To disentangle each vibrational mode contributing to the experimental broad bands, we run a best non-linear fit between the predicted set of frequencies and the experimental bands. The outcome of this procedure allowed us to: i) deconvolute the experimental IR spectrum by assigning computed normal modes of vibrations to the main features of each band; ii) reveal which crystal faces are responsible of the largest contribution to the adsorbate vibrational bands, giving information about the morphology of the samples. The present straigthforward procedure is quite general and of broad interest in the fine characterization of the infrared spectra of adsorbates on complex inorganic material surfaces.

cond-mat.mtrl-sci↗

arXiv2024

Delivery of DART Impact Ejecta to Mars and Earth: Opportunity for Meteor Observations

NASA's DART and ESA's Hera missions offer a unique opportunity to investigate the delivery of impact ejecta to other celestial bodies. We performed ejecta dynamical simulations using 3 million particles categorized into three size populations (10 cm, 0.5 cm, and 30 $μ$m) and constrained by early post-impact LICIACube observations. The main simulation explored ejecta velocities ranging from 1 to 1,000 m/s, while a secondary simulation focused on faster ejecta with velocities from 1 to 2 km/s. We identified DART ejecta orbits compatible with the delivery of meteor-producing particles to Mars and Earth. Our results indicate the possibility of ejecta reaching the Mars Hill sphere in 13 years for launch velocities around 450 m/s, which is within the observed range. Some ejecta particles launched at 770 m/s could reach Mars's vicinity in 7 years. Faster ejecta resulted in a higher flux delivery towards Mars and particles impacting the Earth Hill sphere above 1.5 km/s. The delivery process is slightly sensitive to the initial observed cone range and driven by synodic periods. The launch locations for material delivery to Mars were predominantly northern the DART impact site, while they displayed a southwestern tendency for the Earth-Moon system. Larger particles exhibit a marginally greater likelihood of reaching Mars, while smaller particles favor delivery to Earth-Moon, although this effect is insignificant. To support observational campaigns for DART-created meteors, we provide comprehensive information on the encounter characteristics (orbital elements and radiants) and quantify the orbital decoherence degree of the released meteoroids.

astro-ph.EP↗

arXiv2024

FAUST XIX. D$_2$CO in the outflow cavities of NGC\,1333 IRAS\,4A: recovering the physical structure of its original prestellar core

Molecular deuteration is a powerful diagnostic tool for probing the physical conditions and chemical processes in astrophysical environments. In this work, we focus on formaldehyde deuteration in the protobinary system NGC\,1333 IRAS\,4A, located in the Perseus molecular cloud. Using high-resolution ($\sim$\,100\,au) ALMA observations, we investigate the [D$_2$CO]/[HDCO] ratio along the cavity walls of the outflows emanating from IRAS\,4A1. Our analysis reveals a consistent decrease in the deuteration ratio (from $\sim$\,60-20\% to $\sim$\,10\%) with increasing distance from the protostar (from $\sim$\,2000\,au to $\sim$\,4000\,au). Given the large measured [D$_2$CO]/[HDCO], both HDCO and D$_2$CO are likely injected by the shocks along the cavity walls into the gas-phase from the dust mantles, formed in the previous prestellar phase. We propose that the observed [D$_2$CO]/[HDCO] decrease is due to the density profile of the prestellar core from which NGC\,1333 IRAS\,4A was born. When considering the chemical processes at the base of formaldehyde deuteration, the IRAS\,4A's prestellar precursor had a predominantly flat density profile within 3000\,au and a decrease of density beyond this radius.

astro-ph.GA↗

arXiv2024

Binding Energies and Vibrational Spectral Features of S$_n$ Species on Amorphous Water-ice Mantles: A Quantum Mechanical Study

In the denser and colder regions of the interstellar medium (ISM), gas-phase sulfur is depleted by 2 or 3 orders of magnitude with respect to its cosmic abundance. Thus, which species are the main carriers of sulfur is an open question. Recent studies have proposed S$_n$ species as potential sulfur reservoirs. Among the various sulfur allotropes, the most stable one is the S$_8$ ring, detected in the asteroid Ryugu and Orgueil meteorite. Shorter species, namely S$_3$ and S$_4$, have been found in the comet 67P/C-G, but their presence in the ISM remains elusive. In this study, we compute the binding energies (BEs) of S$_n$ (n = 1-8) species on an amorphous water-ice surface model and analyze their infrared (IR) and Raman spectral features to provide data for their identification in the ISM. Our computations reveal that these species exhibit lower BEs than previously assumed and that their spectral features experience minimal shifts when adsorbed on water ice, because of the weak and nonspecific S$_n$-ice interactions. Furthermore, these species display very low IR band intensities and, therefore, very accurate instruments operating in the mid-IR range are required for detecting the presence of these species in dense interstellar environments.

astro-ph.GA↗

arXiv2024

Binding energies of ethanol and ethylamine on interstellar water ices: synergy between theory and experiments

Experimental and computational chemistry are two disciplines to conduct research in Astrochemistry, providing essential reference data for both astronomical observations and modeling. These approaches not only mutually support each other, but also serve as complementary tools to overcome their respective limitations. We characterized the binding energies (BEs) of ethanol (CH$_3$CH$_2$OH) and ethylamine (CH$_3$CH$_2$NH$_2$), two interstellar complex organic molecules (iCOMs), onto crystalline and amorphous water ices through density functional theory (DFT) calculations and temperature programmed desorption (TPD) experiments. Experimentally, CH$_3$CH$_2$OH and CH$_3$CH$_2$NH$_2$ behave similarly, in which desorption temperatures are higher on the water ices than on a bare gold surface. Computed cohesive energies of pure ethanol and ethylamine bulk structures allow describing the BEs of the pure species deposited on the gold surface, as extracted from the TPD curve analyses. The BEs of submonolayer coverages of CH$_3$CH$_2$OH and CH$_3$CH$_2$NH$_2$ on the water ices cannot be directly extracted from TPD due to their co-desorption with water, but they are computed through DFT calculations, and found to be greater than the cohesive energy of water. The behaviour of CH$_3$CH$_2$OH and CH$_3$CH$_2$NH$_2$ is different when depositing adsorbate multilayers on the amorphous ice, in that, according to their computed cohesive energies, ethylamine layers present weaker interactions compared to ethanol and water. Finally, from the computed BEs of ethanol, ethylamine and water, we can infer that the snow-lines of these three species in protoplanetary disks will be situated at different distances from the central star. It appears that a fraction of ethanol and ethylamine is already frozen on the grains in the water snow-lines, causing their incorporation in water-rich planetesimals.

physics.chem-ph↗

arXiv2024

Multiple chemical tracers finally unveil the intricate NGC\,1333 IRAS\,4A outflow system. FAUST XVI

The exploration of outflows in protobinary systems presents a challenging yet crucial endeavour, offering valuable insights into the dynamic interplay between protostars and their evolution. In this study, we examine the morphology and dynamics of jets and outflows within the IRAS\,4A protobinary system. This analysis is based on ALMA observations of SiO(5--4), H$_2$CO(3$_{0,3}$--2$_{0,3}$), and HDCO(4$_{1,4}$--3$_{1,3}$) with a spatial resolution of $\sim$150\,au. Leveraging an astrochemical approach involving the use of diverse tracers beyond traditional ones has enabled the identification of novel features and a comprehensive understanding of the broader outflow dynamics. Our analysis reveals the presence of two jets in the redshifted emission, emanating from IRAS\,4A1 and IRAS\,4A2, respectively. Furthermore, we identify four distinct outflows in the region for the first time, with each protostar, 4A1 and 4A2, contributing to two of them. We characterise the morphology and orientation of each outflow, challenging previous suggestions of bends in their trajectories. The outflow cavities of IRAS\,4A1 exhibit extensions of 10$''$ and 13$''$ with position angles (PA) of 0$^{\circ}$ and -12$^{\circ}$, respectively, while those of IRAS\,4A2 are more extended, spanning 18$''$ and 25$''$ with PAs of 29$^{\circ}$ and 26$^{\circ}$. We propose that the misalignment of the cavities is due to a jet precession in each protostar, a notion supported by the observation that the more extended cavities of the same source exhibit lower velocities, indicating they may stem from older ejection events.

astro-ph.GA↗

arXiv2024

Mechanical Properties of Minerals in Lunar and HED Meteorites from Nanoindentation Testing: Implications for Space Mining

This study analyzes the mechanical and elemental properties of lunar meteorites DHOFAR 1084, JAH 838, NWA 11444, and HED meteorite NWA 6013. Utilizing microscale rock mechanics experiments, i.e., nanoindentation testing, this research reveals significant heterogeneity in both mechanical and elemental attributes across the minerals of the samples. Olivines, pyroxen, feldspar, and spinel demonstrate similar compositional and mechanical characteristics. Conversely, other silicate and oxide minerals display variations in their mechanical properties. Terrestrial olivines subjected to nanoindentation tests exhibit increased hardness and a higher Young's modulus compared to their lunar counterparts. A linear correlation is observed between the H/Er ratio and both plastic and elastic energies. Additionally, the alignment of mineral phases along a constant H/Er ratio suggests variations in local porosity. This study also highlights the need for further research focusing on porosity, phase insertions within the matrix, and structural orientations to refine our understanding of these mechanical characteristics. The findings have direct implications for in-situ resource utilization (ISRU) strategies and future state-of-the-art impact models. This comprehensive characterization serves as a foundational resource for future research efforts in space science and mining.

cond-mat.mtrl-sci↗

arXiv2024

Theoretical modelling of the adsorption of neutral and charged sulphur-bearing species on to olivine nanoclusters

Sulphur depletion in the interstellar medium (ISM) is a long-standing issue, as only 1% of its cosmic abundance is detected in dense molecular clouds (MCs), while it does not appear to be depleted in other environments. In addition to gas phase species, MCs also contain interstellar dust grains, which are irregular, micron-sized, solid aggregates of carbonaceous materials and/or silicates. Grains provide a surface where species can meet, accrete, and react. Although freeze-out of sulphur onto dust grains could explain its depletion, only OCS and, tentatively, SO$_2$ were observed on their surfaces. Therefore, it is our aim to investigate the interaction between sulphur-containing species and the exposed mineral core of the grains at a stage prior to when sulphur depletion is observed. Here, the grain core is represented by olivine nanoclusters, one of the most abundant minerals in the ISM, with composition Mg$_4$Si$_2$O$_8$ and Mg$_3$FeSi$_2$O$_8$. We performed a series of quantum mechanical calculations to characterize the adsorption of 9 S-bearing species, both neutral and charged, onto the nanoclusters. Our calculations reveal that the Fe-S interaction is preferred to Mg-S, causing sometimes the chemisorption of the adsorbate. These species are more strongly adsorbed on the bare dust grain silicate cores than on water ice mantles, and hence therefore likely sticking on the surface of grains forming part of the grain core. This demonstrates that the interaction of bare grains with sulphur species in cloud envelopes can determine the S-depletion observed in dense molecular clouds.

astro-ph.GA↗

arXiv2023

Single-atom catalysis in space: Computational exploration of Fischer Tropsch reactions in astrophysical environments

Gas-phase chemistry at extreme conditions (low densities and temperatures) is difficult, so the presence of interstellar grains is especially important for the synthesis of molecules that cannot form in the gas phase. Interstellar grains are advocated to enhance the encounter rate of the reactive species on their surfaces and to dissipate the energy excess of largely exothermic reactions, but less is known of their role as chemical catalysts that provide low activation energy pathways with enhanced reaction rates. Different materials with catalytic properties are present in interstellar environments, like refractory grains containing space-abundant (d)block transition metals. Quantum chemical calculations considering extended periodic surfaces were carried out in order to search for the stationary points and transitions states to finally construct the reaction potential energy surfaces. Binding energy and kinetic calculations based on the Rice Ramsperger Kassel Marcus (RRKM) scheme were also performed to evaluate the catalytical capacity of the grain and to allocate those reaction processes within the astrochemical framework. Our mechanistic studies demonstrate that astrocatalysis is feasible in astrophysical environments. Thermodynamically the proposed process is largely exergonic, but kinetically it shows energy barriers that would need from an energy input in order to go through. The present results can explain the presence of CH3OH in diverse regions where current models fail to reproduce its observational quantity. The evidence of astrocatalysis opens a completely new spectrum of synthetic routes triggering chemical evolution in space. From the mechanistic point of view the formation of methanol catalysed by a single atom of Fe0 is feasible; however, its dependency on the temperature makes the energetics a key issue in this scenario.

astro-ph.GA↗