In order to explore new magnetic superhalogens, we have systematically investigated the structures, electrophilic properties, stabilities, magnetic properties, and fragmentation channels of neutral and anionic Fe(m)F(n) (m = 1, 2; n = 1-7) clusters using density functional theory. Our results show that a maximum of six F atoms can be bound atomically to one Fe atom, and the Fe-Fe bonding is not preferred in Fe2F(n)(0/-) clusters. The computed electron affinities (EAs) indicate that FeF(n) with n ≥ 3 are superhalogens, while Fe2F(n) can be classified as superhalogens for n ≥ 5. To further understand their superhalogen characteristic, the natural population analysis charge distribution and the HOMOs of anionic clusters were also analyzed. When the extra negative charge and the content of HOMO are mainly located on F atoms, the clusters could be classified as superhalogens with EAs substantially surpass that of Cl. By calculating the binding energies per atom and the HOMO-LUMO gaps, FeF3, FeF4(-), Fe2F4, Fe2F5(-), and Fe2F7(-) clusters were found to have higher stabilities, corresponding to the Fe atoms that are attained at their favorite +2 and +3 oxidation states. Furthermore, we also predicted the most preferred fragmentation channel and product for all the ground state clusters. Even more striking is the fact that both neutral and anionic Fe(m)F(n) (m = 1, 2; n = 1-7) clusters carry large magnetic moments which mainly come from 3d orbital of iron atom.

The TM-doped Si-based semiconductor clusters have aroused increased attention in a lot of fields. Here, we have performed a structural search of the global minimum for neutral and anionic Si n and La2Si n (n = 1–12) clusters by utilizing the efficient CALYPSO structural searching method with subsequent DFT optimization at the B3LYP level. A large population of low energetic and stable clusters is obtained, and then, the most stable isomers for different cluster sizes are confirmed in light of their total energy and PES spectra. The effect of dopants on the geometries and electronic properties of silicon clusters and their anions are investigated. It is found that the La atoms as well as charges generate distinct influences on them. In all most stable structures of La2Si n 0/–, the impurity La atoms prefer the convex-capped positions of the skeleton and act as the electron donators. The analysis of stability reveals that La2Si3 with a bitriangular pyramid framework is very stable across the cluster size range of n = 1–12. The reason might be that there is pd hybridization between the Si and La atoms leading to strong Si–La bonds in the La2Si3 cluster. This finding is supported by the multicenter bonds and the Mayer bond order analysis.

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Non-precious metal-based electrocatalysts with high activity and stability for efficient hydrogen evolution reactions are of critical importance for low-cost and large-scale water splitting.

We introduced a novel carbon mononitride within tetragonal P4 2 /m symmetry motivated by experimental synthesis and theoretical predictions. Phonon dispersion and formation enthalpy calculations suggest that P4 2 /m-CN is dynamically stable at ambient conditions and can be synthesized at readily attainable pressures. The crystal orientation dependences of the Young's and shear moduli have been systematically studied for this P4 2 /m phase. Further mechanical calculations suggested that the P4 2 /m-CN is ultracompressible and superhard. The ideal tensile and shear strength at large strains of P4 2 /m-CN are also examined. The results suggest that the weakest tensile strength is along the [100] direction, and the atomic deformation mechanism of P4 2 /m-CN along the weakest shear strength direction (100)[010] is discussed.

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Bimetallic clusters have aroused increased attention because of the ability to tune their own properties by changing size, shape, and doping. in present work, a structural search of the global minimum for divalent bimetal Be 2 Mg n (n = 1-20) clusters are performed by utilizing CALYPSO structural searching method with subsequent Dft optimization. We investigate the evolution of geometries, electronic properties, and nature of bonding from small to medium-sized clusters. it is found that the structural transition from hollow 3D structures to filled cage-like frameworks emerges at n = 10 for Be 2 Mg n clusters, which is obviously earlier than that of Mg n clusters. the Be atoms prefer the surface sites in small cluster size, then one Be atom tend to embed itself inside the magnesium motif. At the number of Mg larger than eighteen, two Be atoms have been completely encapsulated by caged magnesium frameworks. in all Be 2 Mg n clusters, the partial charge transfer from Mg to Be takes place. An increase in the occupations of the Be-2p and Mg-3p orbitals reveals the increasing metallic behavior of Be 2 Mg n clusters. the analysis of stability shows that the cluster stability can be enhanced by Be atoms doping and the Be 2 Mg 8 cluster possesses robust stability across the cluster size range of n = 1-20. There is s-p hybridization between the Be and Mg atoms leading to stronger Be-Mg bonds in Be 2 Mg 8 cluster. this finding is supported by the multi-center bonds and Mayer bond order analysis. Scientific RepoRtS |(2020) 10:6052 | https://doi.

The density functional method with relativistic effective core potential has been employed to investigate systematically the geometrical structures, relative stabilities, growth-pattern behaviors, and electronic properties of small bimetallic M(2)Au(n) (M = Ag, Cu; n = 1-10) and pure gold Au(n) (n ≤ 12) clusters. The optimized geometries reveal that M(2) substituted Au(n+2) clusters and one Au atom capped M(2)Au(n-1) structures are dominant growth patterns of the stable alloyed M(2)Au(n) clusters. The calculated averaged atomic binding energies, fragmentation energies, and the second-order difference of energies as a function of the cluster size exhibit a pronounced even-odd alternation phenomenon. The analytic results exhibit that the planar structure Ag(2)Au(4) and Cu(2)Au(2) isomers are the most stable geometries of Ag(2)Au(n) and Cu(2)Au(n) clusters, respectively. In addition, the HOMO-LUMO gaps, charge transfers, chemical hardnesses and polarizabilities have been analyzed and compared further.