The pursuit of atomically precise molecular clusters favors the finding of potential nano-sized species, improving their fundamental understanding. Here, we predict a Sc@Ag16+ cluster featuring a sixteen-vertex endohedral architecture, which resembles the characterized Rh4B12 ligand-decorated metallaborane, pushing the classical icosahedral limit. The electronic structure is given by a 18-cluster electron 1S21P61D10 superatomic configuration with an inherent formation of a long-range shielding cone for any orientation of the external field, confirming its spherical aromatic character. These results reveal Sc@Ag16+ as a truly spherical aromatic superatom, providing grounds for designing principles aiming non-icosahedral atom-precise metallic nanoclusters, as a template for medium-sized species.
Roaming dynamics can provide an alternative to conventional transition state pathways and have been observed in acetaldehyde using XUV time-resolved photoelectron spectroscopy (XUV-TRPES) at 262–308 nm. Alongside CH3 roaming, acetyl radical formation was tentatively assigned at 308 nm, although its mechanism remained unclear. Here, we revisit acetyl formation following 308 nm excitation using multireference and coupled cluster calculations and reanalyse previously reported XUV-TRPES measurements. Although a shallow H-atom roaming region is identified on S1, its predicted spectral signatures are absent experimentally. Instead, the results support a mechanism of CH3 roaming followed by recombination and ground state H-atom loss.
For a reliable molecular dynamics (MD) simulation the total energy of a machine learning potential (MLP) must be conserved in the microcanonical ensemble. We validate the energy conservation of atomic energy models obtained from the Interacting Quantum Atoms (IQA) energy decomposition, implemented in the FFLUX MLP. The IQA recovery error does not compromise the conservation of energy. Monitoring a FFLUX trajectory highlights unphysical geometries undetected by a stability test focused only on the physicality of bond lengths. IQA rationalises the system's energy flow during an NVE simulation, thereby identifying atoms that undergo rapid energy relaxations and those that are spectators.
D-D-π-A dyes with carbazole-phenothiazine donors and cyanoacrylic acid acceptors are a dye-sensitized solar cell (DSSC) focus for tunability, charge transfer, and light harvesting. Theoretical calculations analyzed CP-Ph and CP-Ph-Cl and designed CP-TTT and CP-TBT with -TTT and -TBT π-bridges. Computational results showed improved planarity, narrowed energy gap (Eg), red-shifted absorption, and enhanced light-harvesting efficiency (LHE). The designed dyes had lower ionization potential (IP) and chemical hardness (η), higher polarizability (α) and first hyperpolarizability (βtot), indicating charge separation and transport. They showed higher short-circuit current density (JSC) and power conversion efficiency (PCE) (CP-TTT: 6.73%, CP-TBT: 6.01%), supporting DSSC sensitizer potential.
