Super-electrophiles of tri- and tetra-anions stabilized by selected terminal groups and their role in binding noble gas atoms.

Stabilization of multiply-charged atomic clusters in the gas phase has been a topic of great interest not only because of their potential applications as weakly-coordinating anions, but also for their ability to promote unusual reactions and serve as building blocks of materials. Recent experiments have shown that, after removing one terminal ligand from the -dodecacyano-borate, B(CN), the cluster can strongly bind an argon atom at room temperature. Bearing this in mind, here, we have developed more than a dozen highly stable tri- and tetra-anions using density functional theory (DFT) calculations with hybrid functional (B3LYP) and semi-empirical dispersion corrections.

Record-high stability and compactness of multiply-charged clusters aided by selected terminal groups.

Multiply-charged clusters with compact sizes that are stable in the gas phase are important due to their potential applications as weakly-coordinating ions and building blocks of bulk materials. However, the number of these clusters, especially those with high charge states beyond two, is limited. In this work, we show that gas-phase di- and tri-anions with record-high stability and compactness can be developed by utilizing a series of stable mono-anions with linear configurations as ligands.

New Theoretical Insights into the Crystal-Field Splitting and Transition Mechanism for Nd-Doped YAlO.

There has been considerable research interest paid to rare-earth transition-metal-doped YAlO, which has great potential for application as a laser crystal of new-type laser devices because of its unique optoelectronic and photophysical properties. Here, we present new research conducted on the structural evolution and crystal-field characteristics of a rare-earth Nd-doped YAlO laser crystal by using the CALYPSO structure search method and our newly developed WEPMD method. A novel cage-like structure with a Nd concentration of 4.

Deciphering the Microstructure and Energy-Level Splitting of Tm-Doped Yttrium Aluminum Garnet.

Thulium-doped yttrium aluminum garnet (Tm:YAG) is an important solid-state laser crystal. The energy-level splitting within it is still an unresolved problem. Here, we perform a theoretical study on the microstructure of Tm-doped YAG using the CALYPSO structure search method in conjunction with first-principles calculations.

Role of ligands in the stability of BX and CBX (n = 5-10; X = H, F, CN) and their potential as building blocks of electrolytes in lithium ion batteries.

Stabilizing small multiply charged negative ions in the gas phase has been of considerable interest in recent years. BH is one of the most well-known dianions which is stable against auto-detachment of its second electron in the gas phase by 0.9 eV, whereas BH with n < 12 is unstable.

Chemisorption-induced two- to three-dimensions structural transformations in gold pentamer (CO)(n)Au5(-) (n =0-5).

Understanding the geometry structures of gold clusters, especially with adsorbates, is essential for designing highly active gold nanocatalysts. Here, CO chemisorption onto the Au5(-) cluster is investigated using the density functional calculations. It is found that chemisorption of CO molecules can induce previously unreported two- to three-dimensions (3D) structural changes.

Probing the structural and electronic properties of small aluminum dideuteride clusters.

Adsorption of deuterium on the neutral and anionic Aln(λ) (n=1-9, 13; λ=0, -1) clusters has been investigated systematically using density functional theory. The comparisons between the Franck-Condon factor simulated spectra and the measured photoelectron spectroscopy (PES) of Cui and co-workers help to search for the ground-state structures. The results showed that D2 molecule tends to be dissociated on aluminum clusters and forms the radial AlD bond with one aluminum atom.

Phase stability, mechanical properties, hardness, and possible reactive routing of chromium triboride from first-principle investigations.

The first-principles calculations are employed to provide a fundamental understanding of the structural features and relative stability, mechanical and electronic properties, and possible reactive route for chromium triboride. The predicted new phase of CrB3 belongs to the rhombohedral phase with R-3m symmetry and it transforms into a hexagonal phase with P-6m2 symmetry at 64 GPa. The mechanical and thermodynamic stabilities of CrB3 are verified by the calculated elastic constants and formation enthalpies.

Formation and properties of iron-based magnetic superhalogens: a theoretical study.

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.

Evolution of structure and properties of neutral and negatively charged transition metal-coronene complexes: a comprehensive analysis.

The geometries, electronic and magnetic properties of neutral and negatively charged Mn(coronene)m (M = V and Ti; n, m = 1, 2) complexes were investigated using density functional theory. The results show that one V or Ti atom prefers to occupy the η(6)-site in M(coronene)(0/-) complexes and to be sandwiched between the two coronene molecules in M(coronene)2(0/-) complexes. Two metal atoms always form a dimer and interact with one coronene molecule.

Probing the structural, electronic and magnetic properties of multicenter Fe₂S₂⁰/⁻, Fe₃S₄⁰/⁻ and Fe₄S₄⁰/⁻ clusters.

The structural, electronic and magnetic properties of neutral and anion Fe2S2, Fe3S4 and Fe4S4 have been investigated with the aid of previous photoelectron spectroscopy and density functional theory calculations. Theoretical electron detachment energies (both vertical and adiabatic) of anion clusters for the lowest energy structure were computed and compared with the experimental results to verify the ground states. The optimized structures show that the ground state structures of Fe2S2(0/-), Fe3S4(0/-) and Fe4S4(0/-) favor high spin state and are similar to their structures in proteins.

Probing the structural and electronic properties of aluminum-sulfur AlnSm (2≤n+m≤6) clusters and their oxides.

Using the first-principle density functional calculations, the equilibrium geometries and electronic properties of anionic and neutral aluminum-sulfur AlnSm (2≤n+m≤6) clusters have been systematically investigated at B3PW91 level. The optimized results indicate that the lowest-energy structures of the anionic and neutral AlnSm clusters prefer the low spin multiplicities (singlet or doublet) except the Al2‾, Al2, S2, Al4 and Al2S4 clusters. A significant odd-even oscillation of the highest occupied-lowest unoccupied molecular orbital (HOMO-LUMO) energy gaps for the AlnSm‾ clusters is observed.