Machine learning interatomic potentials (MLIPs) offer a promising route for accurate and transferable modeling of oxide glasses; however, their performance for complex aluminosilicate compositions remains insufficiently benchmarked. In this work, we systematically assess several pretrained MLIPs (DeePMD, DeePMD-D3, MP0, MP0-D3, MATPES, and MATPES-D3) together with an empirical force field (BMP) against experimental data for albite and anorthite glasses. Structural properties-including density, pair distribution functions, coordination numbers, Qn species distributions, bridging statistics, and bond-angle distributions-as well as the pressure-induced variation of Al coordination (in the anorthite glass only) are evaluated and compared with experimental diffraction and NMR data. The elastic properties such as young's and bulk moduli are also investigated. All models reproduce the short-range tetrahedral order of Si and Al, and correctly capture the compositional stiffness trend between albite and anorthite. The inclusion of dispersion corrections in the MLIPs systematically increases density, modifier coordination, and elastic stiffness. However, Qn distributions and medium-range connectivity are not improved by MLIPs relative to BMP, and none of the pretrained models quantitatively reproduces experimental elastic constants. Under compression, the MLIPs successfully reproduce the pressure-invariant Si & horbar;O bond length and the pressure-induced increase in Al coordination, with MATPES-D3 providing the closest agreement with experimental coordination trends. Overall, pretrained MLIPs provide reliable structural trends and improved transferability under pressure, but do not consistently outperform the empirical model for medium-range topology or mechanical properties, highlighting the need for glass-specific fine-tuning.

Among the biogenic macroelements, phosphorus is the one bringing the most fascinating and unsolved mysteries concerning 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 are the subject of this kinetic computational study, which complements our previous thermodynamic characterization. The reaction was studied at the periodic DFT level, simulating the water corrosion reaction on the reactive Fe2NiP schreibersite (001) surface. Results show that the time scale of the reaction at 350 K is a few hours.

Understanding the catalytic role of cosmic mineral surfaces is crucial for elucidating the chemical evolution needed for the emergence of life on Earth and other planetary systems. In this study, the catalytic role of silicate forsterite (Mg2SiO4) surfaces in the synthesis of iminoacetonitrile (IAN, HN=CH-CN) from the condensation of two hydrogen cyanide (HCN) molecules is investigated through quantum mechanical simulations. Using density functional theory calculations, the potential energy surfaces alongside the kinetics of various surface-mediated reactions leading to the formation of IAN are characterized. The effectiveness of forsterite as a catalyst is a delicate balance of the surface reactivity: on one side, the deprotonation of HCN is mandatory to trigger the dimerization; on the other side, the species should be weakly bound to the surface, thus allowing for their diffusion to meet with each other. The work reveals interesting counterintuitive results: the (120) and (101) forsterite surfaces (the less reactive ones) exhibit favorable catalytic properties for the reaction, in detriment to the (111) one (one of the most reactive). The implications of these findings in the astrobiology and prebiotic chemistry fields and for laboratory experiments are discussed, highlighting the potential role of cosmic silicates in the synthesis of complex organic molecules.

Cyclodextrin-based nanosponges are cross-linked polymeric porous nanomaterials obtained by condensation of cyclodextrins with a polyfunctional reagent (cross-linker). Owing to their high surface area, they are attractive for encapsulation applications aimed at increasing the stability, solubility, and bioavailability of drugs. Due to the structural complexity of these emerging materials, computer modeling can provide atomistic-level insights into both the flexibility of nanosponges and their interactions with encapsulated drugs. In this contribution, we focus on nanosponges of β-cyclodextrin cross-linked with citric acid and provide full-atom models for linear and cyclic topologies. We use extensive molecular dynamics (MD) simulations to analyze the flexibility of these constructs and their interactions with encapsulated melatonin, a neurohormone involved in sleep-wake cycle regulation also used as an antioxidant and immunomodulator. We characterize the main interactions responsible for melatonin binding and show that it benefits from multivalence and crowding effects.

In the coldest, densest regions of the interstellar medium (ISM), dust grains are covered by thick ice mantles dominated mainly by water. Although more than 300 species have been detected in the gas phase of the ISM by their rotational emission lines within the radio frequency range, only a few were found in interstellar ices, e.g. CO, CO2, NH3, CH3OH, CH4 and OCS, by means of infrared (IR) spectroscopy. Observations of ices require a background-illuminating source for absorption, constraining the available sight lines for investigation. Further challenges arise when comparing with laboratory spectra due to the influence of temperature, ice structure and the presence of other species. In the era of IR observations provided by the James Webb space telescope (JWST), it is crucial to provide reference spectral data confirming JWST's assigned features. For this purpose, this study addresses the adsorption of the aforementioned species on water ice surfaces and their IR features by means of quantum chemical computations grounded on the density functional theory (DFT) hybrid B3LYP-D3(BJ) functional, known to give reliable results for binding energy and vibrational frequency calculations, including IR spectra simulation. The calculated binding energies and IR spectral data are presented in the context of experimental spectra of ices and the new findings from the JWST, which have already proven to be insightful thanks to its unmatched sensitivity. We show that quantum chemistry is a powerful tool for accurate frequency calculations of ISM ice interfaces, providing unprecedented insights into their IR signatures.

Hydrogen cyanide, HCN, is a fundamental building block in astro- and cosmochemical environments, known for its ability to form prebiotically relevant molecules such as nucleobases. Although its polymerization is inhibited under the cold, dilute conditions of the interstellar medium, the higher temperatures of more evolved rocky bodies, combined with the presence of mineral surfaces, can catalyze the reaction. In this study, we use atomistic simulations grounded on the density functional theory (DFT) to elucidate the complete tetramerization pathway of HCN to diaminomaleonitrile (DAMN) and diaminofumaronitrile (DAFN), catalyzed by the crystalline Mg2SiO4 forsterite (120) surface. Results demonstrate that the intrinsic acid-base properties of the surface facilitate chemical bond formation/cleavage needed for HCN oligomerization, lowering activation barriers by ∼120-220 kJ mol-1 with respect to the gas-phase. Kinetic analyses reveal that the reactions are feasible at temperatures above 300 K, particularly under conditions present in warm, rocky bodies such as asteroids, meteorites, and planetary surfaces. The presence of water further accelerates key steps by assisting proton transfer processes. These findings support a model in which Mg-rich silicate minerals (abundant in the early Solar System) may have directly catalyzed the formation of complex organic molecules, which, in turn, are precursors of more complex biomolecules, thereby contributing to the essential chemical inventory for the emergence of life on early Earth and other primitive planets with propitious conditions.

Combining IR spectroscopy and DFT modelling, we show that in shape-engineered TiO2 anatase nanoparticles capping agents’ thermal removal leads to a reconstruction of {001} facets compatible with the “add-oxygen” and not with the “add-molecule” model.

Asteroids are the most ancient bodies of a planetary system, mostly formed during the accretion of the protoplanetary disk. They can be made of either rocky and metallic materials, and they are sources of important species which are fundamental for the emergence of life on planets. In our history, during the heavy late bombardment (4.0−3.8 Gya ago), a large quantity of meteorites (the asteroids that impact a planet) fall onto the earth crust, bringing several interstellar complex organic molecules, as well as other species (like phosphorus), produced during the early stages of the solar system formation.1 In recent years we have carried out periodic quantum mechanical simulations on forsterite (Mg2SiO4) and schreibersite (Fe2NiP) as archetype of rocky and iron meteorites, respectively. In particular, the former was studied through a synergistic interaction between experiments (infrared spectroscopy and high-mass resolution spectrometry) and atomistic simulations, elucidating the reactivity of HCN towards its polymerization, up to the formation of adenine, one of the DNA components.2,3 The latter system is a source of reactive phosphorus that, from the interaction with water, undergoes corrosion with the formation of oxygenated phosphorus compounds. In our work, we demonstrated the favorable exergonic formation of phosphates and, moreover, that such phosphates are in turn activated by the surface to phosphorylate other molecules, like sugars and nucleobases.4,5,6[1] M. Pasek, D. Lauretta, Origins Life Evol. Biospheres 2008, 38, 5−21[2] N. Bancone, S. Pantaleone, P. Ugliengo, A. Rimola, M. Corno, Phys. Chem. Chem. Phys. 2023, 25, 26797-26812[3] R. Santalucia, M. Pazzi, F. Bonino, M. Signorile, D. Scarano, P. Ugliengo, G. Spoto, L. Mino, Phys. Chem. Chem. Phys. 2022, 24, 7224-7230[4] S. Pantaleone, M. Corno, A. Rimola, N. Balucani, P. Ugliengo, ACS Earth Space Chem. 2021, 5, 7, 1741–1751[5] S. Pantaleone, M. Corno, A. Rimola, N. Balucani, P. Ugliengo, J. Phys. Chem. C 2022, 126, 4, 2243–2252[6] S. Pantaleone, M. Corno, A. Rimola, N. Balucani, P. Ugliengo, ACS Earth Space Chem. 2023, 7, 10, 2050–2

Because substitutions of BH4- anion with Br can stabilize the hexagonal structure of the LiBH4 at room temperature, leading to a high Li-ion conductivity, its thermodynamic stability has been investigated in this work. The binary LiBH4-LiBr system has been explored by means of X-ray diffraction and differential scanning calorimetry, combined with an assessment of thermodynamic properties. The monophasic zone of the hexagonal Li(BH4)1-x(Br)x solid solution has been defined from x=0.30 to x=0.55 at room temperature. Solubility limits have been determined by in-situ X-ray diffraction at various temperatures. For the formation of the h-Li(BH4)0.6(Br)0.4 solid solution, a value of the enthalpy of mixing has been determined experimentally equal to 1.0 kJ/mol. In addition, the enthalpy of melting has been measured for various compositions. Lattice stabilities of LiBH4 and LiBr have been determined by ab initio calculations, using CRYSTAL and VASP codes. Combining results of experiments and theoretical calculations, the LiBH4-LiBr phase diagram has been determined in all composition and temperature range by the CALPHAD method.

Despite hydrogen sulphide (H2S) has been predicted to be the major reservoir of S-bearing species on the icy mantles of interstellar grains, no solid H2S has been detected so far. A crucial parameter that governs whether or not a species remains frozen on to the grain mantles is its binding energy (BE). We present a new computational study of the H2S BE on a large amorphous water ice surface, constituted by 200 water molecules. The resulting H2S BE distribution ranges from 57 K (0.5 kJ mol-1) to 2406 K (20.0 kJ mol-1), with the average mu = 984 K (8.2 kJ mol-1). We discuss the reasons why the low bound of the newly computed BE distribution, which testifies to the very weak interaction of H2S with the ice surface, has never been found by previous theoretical or experimental works before. In addition, the low H2S BEs may also explain why frozen H2S is not detected in interstellar ices. Following previous molecular dynamics studies that show that the energy of reactions occurring on ice surfaces is quickly absorbed by the water molecules of the ice and conservatively assuming that 10 per cent of the HS + H -> H2S formation energy (-369.5 kJ mol-1) is left to the newly formed H2S, its energy is more than twice the largest BE and five times the average BE and, hence, H2S will most likely leave the water surface.

In the last decade shape-engineering of TiO2 anatase nanoparticles (NPs) has attracted increasing attention owing to the possibility to maximize the presence of {001} facets, which have been reported to show peculiar adsorption, electronic, and (photo)catalytic properties. It is well-known that the anatase (001) surface is prone to reconstruction and several models have been proposed and validated by DFT calculations and single crystal studies. However, its true atomic structure in shape-engineered TiO2 anatase nanoparticles often remains elusive. In this study we shed light on this issue combining IR spectroscopy of CO adsorbed at very low temperature and thorough DFT modelling. Our results show that the thermal treatment in oxygen, performed to remove the capping agents (i.e., fluorides) employed in the synthesis of shape-controlled NPs, leads to a reconstruction of the {001} facets which is compatible with an "add-oxygen" model (AOM) and not with the most commonly reported "add-molecule" model (ADM). These findings can guide future experimental and computational studies highlighting that the AOM reconstruction is the most appropriate model to describe the properties and reactivity of the {001} facets in shape-controlled TiO2 nanoparticles after thermal removal of fluorides.

Melatonin (MT) is a vital hormone controlling biorhythms, and optimizing its release in the human body is crucial. To address MT's unfavorable pharmacokinetics, we explored the inclusion complexes of MT with beta-cyclodextrin (beta-CD). Nano spray drying was applied to efficiently synthesize these complexes in three molar ratios (MT : beta-CD = 1 : 1, 2 : 1, and 1 : 2), reducing reagent use and expediting inclusion. The complex powders were characterized through thermal analyses (TGA and DSC), Fourier transform infrared spectroscopy (FTIR), and in vitro MT release measurements via high-performance liquid chromatography (HPLC). In parallel, computational studies were conducted, examining the stability of MT : beta-CD complexes by means of unbiased semi-empirical conformational searches refined by DFT, which produced a distribution of MT : beta-CD binding enthalpies. Computational findings highlighted that these complexes are stabilized by specific hydrogen bonds and non-specific dispersive forces, with stronger binding in the 1 : 1 complex, which was corroborated by in vitro release data. Furthermore, the alignment between simulated and experimental FTIR spectra demonstrated the quality of both the structural model and computational methodology, which was crucial to enhance our comprehension of optimizing MT's release for therapeutic applications. Melatonin/beta-cyclodextrin complex was studied by means of experimental and computational techniques to optimize the release of the drug over time in the human body.

Nanosizing effects and role of additives in the decomposition of Mg(BH 4 ) 2 were studied by DFT modelling. Decomposition is favoured at the nanoscale with respect to the bulk along with a major catalytic effect of Ni compared to Cu.

The direct/reductive amination of carbohydrate-based furoin and furil with NH 3 /H 2 was investigated to access amine derivatives.

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.

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.

Combining IR spectroscopy and DFT modelling, we show that in shape-engineered TiO 2 anatase nanoparticles capping agents’ thermal removal leads to a reconstruction of {001} facets compatible with the “add-oxygen” and not with the “add-molecule” model.

This Supporting Material contains the fractional coordinates of DFT optimized structures of: _ Forsterite bulk _ The six forsterite surfaces treated in this work _ The 16 HCN-forsterite adsorption complexes _The stationary points for the activated deprotonation of adsorbed species

Phosphorus (P) is a fundamental element for whatever form of life, in the same way as the other biogenic macroelements (SONCH). The prebiotic origin of P is still a matter of debate, as the phosphates present on earth are trapped in almost insoluble solid matrixes (apatites) and, therefore, hardly available for inclusion in living systems in the prebiotic era. The most accepted theories regard a possible exogenous origin during the Archean Era, through the meteoritic bombardment, when tons of reactive P in the form of phosphide ((Fe,Ni)(3)P, schreibersite mineral) reached the primordial earth, reacting with water and providing oxygenated phosphorus compounds (including phosphates). In the last 20 years, laboratory experiments demonstrated that the corrosion process of schreibersite by water indeed leads to reactive phosphates that, in turn, react with other biological building blocks (nucleosides and simple sugars) to form more complex molecules (nucleotides and complex sugars). In the present paper, we study the water corrosion of different crystalline surfaces of schreibersite by means of periodic DFT (density functional theory) simulations. Our results show that water adsorbs molecularly on the most stable (110) surface but dissociates on the less stable (001) one, giving rise to further reactivity. Indeed, subsequent water adsorptions, up to the water monolayer coverage, show that, on the (001) surface, iron and nickel atoms are the first species undergoing the corrosion process and, in a second stage, the phosphorus atoms also get involved. When adsorbing up to three and four water molecules per unit cell, the most stable structures found are the phosphite and phosphate forms of phosphorus, respectively. Simulation of the vibrational spectra of the considered reaction products revealed that the experimental band at 2423 cm(-1) attributed to the P-H stretching frequency is indeed predicted for a phosphite moiety attached to the schreibersite (001) surface upon chemisorption of up to three water molecules.

Melatonin (MT) is a vital hormone controlling biorhythms, and optimizing its release in the human body is crucial. To address MT's unfavorable pharmacokinetics, we have explored inclusion complexes of MT with β-cyclodextrin (β-CD). Nano Spray Drying was applied to efficiently synthesize these complexes in three molar ratios (MT:β-CD 1:1, 2:1, 1:2), reducing reagent use and expediting inclusion. The complex powders underwent characterization through thermal analyses (TGA, DSC), Fourier Transform Infrared Spectroscopy (FTIR), and in vitro MT release measurements via High-Performance Liquid Chromatography (HPLC). In parallel, computational studies were conducted, examining the stability of MT:bCD complexes by means of conformational searches and binding enthalpy calculations. Experimental results confirmed the successful encapsulation of MT in the 1:1 and 1:2 MT:β-CD complexes. Computational findings highlighted that these complexes were stabilized by specific hydrogen bonds and non-specific dispersive forces, with stronger binding in the 1:1 complex, a trend corroborated by in vitro release data. Furthermore, the alignment between simulated and experimental FTIR spectra demonstrated the quality of both the structural model and computational methodology, which have revealed crucial to enhance our understanding of optimizing MT's release for therapeutic applications.