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[Display omitted] • Using DFT and AIMD, hydrogen storage in Li functionalized Si4B32 is reported. • Li atoms can bind strongly to the surface of Si4B32 and do not form cluster. • Li6Si4B32 is suitable for reversible hydrogen storage with 8.922 wt% H2 gravimetric density. • The desorption temperatures of Li6Si4B32.(H2)24 is 281 K. This study investigates the reversible hydrogen storage performance of Lithium (Li)-functionalized heteroborospherene Si 4 B 32 with density functional theory (DFT) methods. The Si 4 B 32 cage can accommodate a maximum of 6Li atoms without clustering, every Li atom can bind up to 4 H 2 molecules. The Li 6 Si 4 B 32 can still keep its integrity after absorbing 24 H 2 molecules. The H 2 gravimetric density is 8.922 wt% with 0.220 eV/H 2 average hydrogen adsorption energy. The desorption temperature of Li 6 Si 4 B 32.(H 2) 24 is 281 K, which indicate H 2 molecules can be successfully released at near room temperature. We draw a conclusion that Li-decorated Si 4 B 32 is a potential candidate for reversible hydrogen storage. [ABSTRACT FROM AUTHOR]

Schematic of spontaneous particle annihilation (at rate λ) and configurations for autocatalytic particle creation (at rate λ / 4) with respect to time t for our realization of LELGA on a d = 2 square lattice. k = 8 is the number of neighbouring pairs of particles. Cells in proposed automata in here undergo state-transitions depending on sums of excited and refractory cells in the neighborhood. • Collision-based computation in reaction-diffusion systems. • Theoretical framework for construction of collision-based processor. • Lattice realization of model based on Cellular Automata. • Model mapping for optimization of Lennard-Jones atomic clusters. From the perspective of cellular-automaton and by exploiting the interactions between travelling and localized waves the Lorentz Excitable Lattice Gas Automata (LELGA) is proposed and applied to the optimization of Lennard-Jones (LJ) atomic clusters. Our approach exploits the fact that a reaction-diffusion phenomenon with self-localized excitations cells which behave like quasi-particles, could be potentially used to implement dynamical computation. As an example of collision-based computation in reaction-diffusion systems based on cellular automata we provided our experimental results for unbiased optimization of Lennard-Jones (LJ) atomic clusters. We also demonstrated that the proposed method has successfully located the known global minima of LJ clusters for configuration space size of N ≤ 383. [ABSTRACT FROM AUTHOR]

[Display omitted] • We have employed the method of atomic cluster expansion (ACE) combined with first-principles density functional theory (DFT) calculations for machine learning, and successfully obtained the force field of the binary Fe-Co alloy. • Using ACE force field, the molecular dynamics simulation of Fe-Co alloy was carried out and the temperature related phase transformation range of Fe-Co alloy was correctly predicted. • The ACE force field is able to predict well the phase transition hysteresis behavior, which contributes to the development of the force field of Fe-Co and the use of molecular dynamics to simulate the physical properties of such alloy materials. The force field describing the calculated interaction between atoms or molecules is the key to the accuracy of many molecular dynamics (MD) simulation results. Compared with traditional or semi-empirical force fields, machine learning force fields have the advantages of faster speed and higher precision. We have employed the method of atomic cluster expansion (ACE) combined with first-principles density functional theory (DFT) calculations for machine learning, and successfully obtained the force field of the binary Fe-Co alloy. Molecular dynamics simulations of Fe-Co alloy carried out using this ACE force field predicted the correct phase transition range of Fe-Co alloy. [ABSTRACT FROM AUTHOR]

In this letter, we discussed the plausible formation of [Au 11 Re] as a superatom with an electronic structure accounted by the 1S 2 1P 6 1D 10 shell order, denoting similar stability to [W@Au 12 ]. The possible hollow or endohedral structures show a variable HOMO-LUMO gap according to the given structure (from 0.33 to 1.30 eV, at the PBE/ZORA level). Our results show that the energy minimum is an endohedral arrangement, where Re is encapsulated in a D 3h -Au 11 cage, retaining a higher gold-dopant stoichiometric ratio. This approach is useful for further rationalization and design of novel superatoms expanding the libraries of endohedral clusters. [ABSTRACT FROM AUTHOR]

The stable structures of Cu–Au–Pt clusters up to 147 atoms are optimized by using an improved adaptive immune optimization algorithm (AIOA-IC method), in which several motifs, such as decahedron, icosahedron, face centered cubic, sixfold pancake, and Leary tetrahedron, are randomly selected as the inner cores of the starting structures. The structures of Cu 8 Au n Pt 30- n ( n = 1–29), Cu 8 Au n Pt 47- n ( n = 1–46), and partial 75-, 79-, 100-, and 147-atom clusters are analyzed. Cu 12 Au 93 Pt 42 cluster has onion-like Mackay icosahedral motif. The segregation phenomena of Cu, Au and Pt in clusters are explained by the atomic radius, surface energy, and cohesive energy. [ABSTRACT FROM AUTHOR]

A systematic study, based on density functional theory and different hybrid functionals for exchange-correlation potential, shows that the electron affinities of organo-zintl clusters [Ge 9 (R) n ] [R = CHO; n = 1, 3] are close to that of chlorine (3.6 eV) and iodine (3.0 eV). A detailed study of the molecular orbitals of these complexes, when compared to those of Al 13 − , Cl − and I − , confirm that they behave as superatoms, mimicking the chemistry of halogens. This study expands the scope of superatoms by including a new class of pseudo-halogens based on ligated organo-Zintl ions. [ABSTRACT FROM AUTHOR]

We present acceleration of the vibrational frequency calculations required in free energy basin-hopping (FEBH) global optimisation using sparse Cholesky factorisation. We describe an interface with the SuiteSparse software package that facilitates these calculations, and present results detailing the accuracy and speedups obtained for atomic clusters and biomolecules. For the larger systems, exploiting sparsity reduces the computational cost by factors of ten to thirty, with no significant loss in accuracy. This approach will therefore provide access to the vibrational density of states, and hence to local harmonic free energies, for structure prediction and thermodynamic properties of more complex systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • This work presents a facile method of cluster size characterization of neat atomic Ar clusters, neat molecular 1, 3, 5‑trichlorobenzene clusters, and core (1, 3, 5-trichlorobenzene) – shell (Ar) clusters. • The experimental results are in qualitative agreement with the semi-empirical scaling law, but effects of the stagnation temperature and pressure on the cluster size are quantitatively different from those predicted by the scaling law. • Our method measures the size of the core and the total size of the cluster, therefore offers information on the thickness of the shell of the core–shell cluster. We report experimental measurements of cluster sizes formed from supersonic expansion of two different species based on the time-of-flight principle. Argon clusters containing aromatic molecules are ionized at 266 nm at a low laser intensity. A high voltage is used to accelerate the heavy cluster ions thereby increasing the sensitivity of a microchannel plate detector. Our measurements of argon clusters, neat molecular clusters, and molecular-Ar clusters, are all in qualitative agreement with results predicted from the scaling law, but the fitting exponents for the dependence of cluster sizes on both the stagnation pressure and temperature are different. [ABSTRACT FROM AUTHOR]

Real space representation of hole and electron distributions of the ground state isomer GaMg 8 - cluster for S0→S6, S0→S12, S0→S19 and S0→S26 excitation. [Display omitted] • The geometrical structure, electronic structure and chemical bond properties of the gas-phase GaMg n - (n = 2–12) clusters has been studied. • The two "seeds" for GaMgn- (n = 2–12) clusters growth has been found. • GaMg 8 - cluster has been confirmed to have the most robust stability. • ELF analysis shows that Mg-Mg covalent bonds start to appear in GaMg 2 - size, which is much earlier than in other "heavy" metal-doped magnesium. Ga-doped magnesium mineral based on the atomic cluster level, gas-phase GaMg n - (n = 2–12), were studied utilizing CALYPSO together with density functional theory. Tetrahedral-like and pyramidal-like structures are found to be "seeds" for GaMg n - (n = 2–12) clusters growth. Relative stability calculations indicate that GaMg 8 - cluster possesses the most robust stability. The natural charge population and natural electron configuration of each atom of each ground state cluster were studied, and their chemical bond properties were also investigated by ELF. Finally, the infrared, Raman and UV–vis spectra of GaMg 8 - cluster and its excited state properties were specially studied by NTO analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structure of liquid Fe-C alloy consists of medium-range order clusters, short-range order cores and free volume. • Iron atoms act in three coordination states, while the carbon atoms stay in the short-range cores and medium-range order clusters. • Medium-range order clusters in Fe-C melt are unstable. • Effects of the temperature and composition on melt order degree are inconsistent, so as to the change of viscosity. A comprehensive investigation on liquid structure and viscosity of Fe-C melts were performed. The result shows that there is actually a medium-range ordered cluster structure in molten iron, which is unstable and will change due to the existence of free volume. Carbon atoms exist in an ordered structure inside the melt, while iron atoms have three coordination states. The reduction of carbon content and the increase of temperature contribute to a low viscosity of molten iron. Meanwhile, the number and size of clusters in the Fe-C melt increase accordingly, but the mechanisms affected by temperature and composition are different. [ABSTRACT FROM AUTHOR]

Potential energy surfaces (PES) of Co clusters with Gupta potential using four parameter sets are characterized in terms of conformational analysis. Their structures are obtained using three optimization algorithms. Three new structures with lower energies for one of these parameter sets are found. For all parameter sets, the structural variation from icosahedron to decahedron to close-packed face centered cubic (FCC) or stacking fault FCC and amorphous motifs is related to the potential range of the parameters. The difference between the PES is investigated, and for a long potential-range parameter, the number of local minima on the PES is extremely large. [ABSTRACT FROM AUTHOR]

A combination of the photoelectron spectrometrics and density functional theory calculations has confirmed bond-order-length-strength (BOLS) predictions on the atomic undercoordination induced local bond contraction, charge densification and bond energy entrapment of lithium (Li) atomic clusters and layer-resolved Li(1 1 0) skins. Analysis also derives the energy level of an isolated Li atom and its shift upon bulk and skin formation, which is beyond the scope of currently available approaches. [ABSTRACT FROM AUTHOR]

[Display omitted] • Small-cluster Approximation, Mars van Krevelin. • CeO 2 Catalysis, Carbon Monoxide, Density Functional Theory. • Reaction pathway. Only a few studies have examined oxidation of CO on pure CeO 2. Here we describe reaction on the (110) surface of CeO 2 with DFT and B3LYP calculations of small clusters, Ce 5 O 12 and Ce 6 O 12. We identified a weak adsorption site (0.21 eV) on top of a cerium atom and a strong site (2.31 eV) binding two oxygens to form a carbonate species. These energies are in accord with previous reports including GGA + U. Increasing the cluster size from Ce 5 O 12 and Ce 6 O 12 to Ce 9 O 12 had no significant effect on the outcome. In addition a Mars-van Krevelen type reaction cycle is investigated involving the reaction of CO with a surface oxygen. A secondary pathway was discovered forming a very stable carbonate species, with the reversible reaction having a high activation barrier. This study is the first to find evidence of an activation barrier for the formation of a carbonate species as an alternative pathway to the desorption of CO 2 on CeO 2 /(110), which would otherwise block the surface activity. We find the approach of modelling catalyst activity using a reduced cluster of atoms is accurate, flexible and advantageous. [ABSTRACT FROM AUTHOR]

[Display omitted] • A set of interatomic distances can represent the structure of atomic clusters. • Thanks to the Cayley-Menger determinant, a structure realising in 3D is obtained. • Very few variables can represent the collective motions in the atomic clusters. • An isomerization of Lennard-Jones and Au 6 + clusters are studied. Atomic clusters generally do not have a clear skeletal structure, and proper representation of their geometry is problematic. Bearing in mind the interactions, one can consider that a set of interatomic distances is a natural choice to represent the structure. However, for large degrees of freedom, redundancy is often a problem. Here, we report the analysis of cluster rearrangements in the metric space. The Cayley-Menger determinant plays a crucial role in overcoming the redundancy and controlling the collective changes of multiple atoms only with few variables. As examples, we discuss atomic rearrangements in the Lennard-Jones and Au 6 + clusters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gas-phase sizes introduce a synergistic combination between using global optimization techniques with high level theory (DFT). • Rationalize the promising activity of AuFe clusters at the atomic level and to form a base for future experimental investigations. • Physico-chemical properties which are significant for the rapidly growing fields of sub-nanoscale and single atom catalysis. The limited mutual solubility between Au and Fe in the bulk scale has inhibited the formation of their alloys. Here we report the lowest energy structures of AuFe alloys in subnanometre scale, employing the Mexican Enhanced Genetic Algorithm coupled with density functional theory. The energetics, structural transitions, and tendency of segregation have been analysed by different stability criteria. Physico-chemical properties for all compositions have been studied using Koopman's approximation. The topological parameters for the metal-metal interactions have been calculated using QTAIM theory. Exploring such valuable theoretical insights is of great importance in investigating new AuFe nanoalloy-based materials for technological applications. [ABSTRACT FROM AUTHOR]

• The Cu 10 Ru superatom with 18-ve is investigated by DFT. • Six low-lying energy isomers with the Ru dopant inside the Cu 10 cage are formed. • The 17-ve counterpart Cu 9 Ru, shows a large electron affinity. • Molecular dynamics simulation confirmed the encapsulation of Ru in Cu 10. Here we discussed the plausible formation of the Cu 10 Ru cluster as a superatomic specie accounted for its 1S21P61D10 shell order. By stochastic structure search on Cu 10 Ru clusters, we found six low-lying cluster isomers with ΔE values from 0.0 to 4.7 kcal∙mol above the ground state denoting an endohedral motif with the Ru dopant inside the Cu 10 cage. By using molecular dynamics simulations we found a clear trend of encapsulation of the Ru atom at low temperatures. These results are useful for further rationalization and design of novel spherical superatoms expanding the libraries of stable endohedral clusters. [ABSTRACT FROM AUTHOR]

• Two external fields were employed to design superatoms. • Ligation was confirmed to lower the AIPs of the Nb 2 N 2 L n clusters. • OEEF can precisely and continuously modulate the EA of Nb 2 N 2 at will. • The ligand field and OEEF are novel strategies in constructing superatoms. By using the density functional theory calculations, two external fields, ligand field and the oriented external electric field (OEEF), were introduced to examine their capability in regulating electronic properties of the polymeric Nb 2 N 2 cluster. The ligation strategy was observed to be able to dramatically lower the AIPs of the ligated Nb 2 N 2 clusters forming superalkalis, while the OEEF was confirmed to have power in continuously and precisely modulating the EAs of Nb 2 N 2 at will leading to the formation of superhalogens. These external fields are considered as novel strategies in superatom design, which may broaden the fundamental science of the superatom framework. [ABSTRACT FROM AUTHOR]

• The bonding properties are similar but not identical in isoelectronic species of nearly planar superatoms. • The change of covalent contribution is related to the decrease of 5f energy level in the actinide embedded planar superatoms. • The bonding is affected by the uncertainty electronic configuration of the intramolecular interaction. The electronic structure of isoelectronic superatoms formed by actinides embedded gold ring, An@Au 6 ([Ac@Au 6 − and Th@Au 6 , [Pa@Au 6 +), have been analyzed to investigate the intramolecular interaction using density functional theory. The bonding properties are similar but not identical. The probability densities of 1P and 1D superatomic molecular orbitals are similar, and compared with 6d orbitals, 5f orbitals show localization behaviors, and the change in their contribution of the covalent bonding relate to the decrease in 5f energy levels. Moreover, additional evidence for the bonding being affected by the uncertainty of electronic configuration could be gathered. [ABSTRACT FROM AUTHOR]

• A series of seventeen-coordinate metal clusters M@Li 17 (M = Ca, Sr, Ba, Sc, Y) have been identified. • M@Li 17 (M = Sc, Y), is highly stable, nonmagnetic, and a large HOMO-LUMO gap. • M@Li 17 (M = Ca, Sr, Ba), is highly stable, but a low spin magnetic moment of 1 μ B and a small HOMO-LUMO gap. Stable metal clusters with high coordination numbers (N > 12) are scarce. In this paper, series of seventeen-coordinate metal clusters M@Li 17 (M = Ca, Sr, Ba, Sc, Y) are proposed, where the lithium atoms compose the outer cage and the hetero-atom is centered. The unique structure is located as a low energy isomer by particle swarm optimisation algorithm. With the geometric and electronic shell closures, the high stability of M@Li 17 (M = Sc, Y) is predictable. For the 19-electron M@Li 17 (M = Ca, Sr, Ba), the electronic configurations are 1S21P61D102S α 12S β 0, which can obtain their stability by forming a low magnetic moment of 1 μ B. [ABSTRACT FROM AUTHOR]