α-Keggin polyoxometalates (POMs) [XW₁₂O₄₀]ⁿ⁻ (X = Al, Si, P, S) are widely used in batteries owing to their remarkable redox activity. However, the mechanism underlying the applications appears inconsistent with the widely accepted covalent bonding nature. Here, first-principles calculations show that XW₁₂ are core–shell structures composed of a shell and an XO₄ⁿ⁻ core, both are stabilized by covalent interactions. Interestingly, owing to the presence of a substantial number of electrons in W₁₂O₃₆ shell, the frontier molecular orbitals of XW₁₂ are not only strongly delocalized but also exhibit superatomic properties with high-angular momentum electrons that do not conform to the Jellium model. Detailed analysis indicates that energetically high lying filled molecular orbitals (MOs) have reached unusually high-angular momentum characterized by quantum number K or higher, allowing for the accommodation of numerous electrons. This attribute confers strong electron acceptor ability and redox activity to XW₁₂. Moreover, electrons added to XW₁₂ still occupy the K orbitals and will not cause rearrangement of the MOs, thereby maintaining the stability of these structures. Our findings highlight the structure–activity relationship and provide a direction for tailor-made POMs with specific properties at atomic level.

Bottom-up constructing all-metal functional materials is challenging, because the metal clusters are prone to lose their original structures during coalensence. In this work, we report that closed-shell coinage metal superatoms can achieve direct chemical bonding without losing their electronic properties. The reason is that the supermolecule formed by two superatoms has the same number of bonding and anti-bonding supermolecular orbitals, in which the bonding orbitals contribute to bonding and the anti-bonding orbitals with anti-phase orbitals delocalized over each monomer to maintain the individual geometric and electronic structural properties. Further analysis indicates the interactions between two superatoms are too weak to break the structure of monomers, which is confirmed by the first-principles molecular dynamics simulations. With these superatoms as the basic units, a series of robust one-dimensional and two-dimensional nanostructures are fabricated. Our findings provide a general strategy to take advantage of superatoms in regulating bonding compared to natural atoms, which paves the way for the bottom-up design of materials with collective properties.

The authors employ the high-density resistivity method during an archaeological investigation of Sumicheng site, an ancient city of the Tang Dynasty, to find evidence of human activities and locate a favorable target for archaeological excavation in the southern part of the outer city. There are two obvious high-resistivity structures, the south wall of the inner city and an ancient building near the south gate along the outer city wall, of which the resistivities are indicative of rammed soil foundations. The south wall of the inner city is continuous but is cut off abruptly to the east, which we suggest it is due to either wall damage or destruction. The resistivity signature of the target area is verified by archaeological excavation, proving the feasibility and effectiveness of implementing the high-density resistivity method for archaeological exploration.

The distinctive electronic bonding properties of actinide-containing clusters have made them the subject of increased attention. Herein, we use density functional theory calculations to examine a unique actinide-encapsulated U@B40 cage structure, revealing that it exhibits a 32-electron (1S²1P⁶1D¹⁰1F¹⁴) closed-shell singlet configuration in which all s, p, d, and f shells of the U atom are filled. Furthermore, the binding energy of 8.22 eV calculated for this cluster implies considerable stability, and the simulated infrared and Raman spectra feature U–B₄₀ stretching and pure B₄₀ breathing vibration modes, respectively. These spectral characteristics may aid future experimental investigations. Thus, this work not only describes a new member of the superatomic family, but also provides a method of encapsulating radioactive actinides.

Proton transfer and chiral conversion via hydrogen bonds (HBs) are important processes in applications such as chiral recognition, enzymatic catalysis, and drug preparation. Herein, we investigate the chiral conversion and interlayer recognition, via concerted intralayer proton transfer (CIPT) processes, of small prismatic water clusters, in the form of bilayer n-membered water rings (BnWRs, n = 4, 5, 6). Density functional theory (DFT) calculations show that despite the small energy variations between the initial and final states of the clusters of less than 0.3 kcal·mol^-1, the vibrational circular dichroism (VCD) spectrum provides clear chiral recognition peaks in the range of 3, 000 to 3, 500 cm^-1. The vibrational modes in this region correspond to stretching of intralayer HBs, which produces strong signals in the infrared (IR) and Raman spectra. The electronic circular dichroism (ECD) spectrum also reveals obvious chiroptical characteristics. The molecular orbitals involved in the interlayer interaction are dominated by O 2p atomic orbitals; the energy of these orbitals increased by up to 0.1 eV as a result of the CIPT processes, indicating corresponding recognition between monolayer water clusters. In addition, isotopic substitution by deuterium in the BnWRs results in characteristic peaks in the VCD spectra that can be used as fingerprints in the identification of the chiral structures. Our findings provide new insights into the mechanism of chiral recognition in small prismatic water clusters at the atomic level as well as incentives for future experimental studies.

Actinide elements encaged in a superatomic cluster can exhibit unique properties due to their hyperactive valence electrons. Herein, the electronic and spectroscopic properties of Th@Au₁₄ are predicted and compared with that of the isoelectronic entities [Ac@Au₁₄]^- and [Pa@Au₁₄]⁺ using density functional theory. The calculation results indicate that these clusters all adopt a closedshell superatomic 18-electron configuration of the 1S²1P⁶1D¹⁰ Jellium state. The absorption spectrum of Th@Au₁₄ can be interpreted by the Jelliumatic orbital model. In addition, calculated spectra of pyridine-Th@Au₁₄ complexes in the blue laser band exhibit strong peaks attributable to charge transfer (CT) from the metal to the pyridine molecule. These charge-transfer bands lead to a resonant surface-enhanced Raman scattering (SERS) enhancement of ~10⁴. This work suggests a basis for designing and synthesizing SERS substrate materials based on actinide-embedded gold superatom models.