Our studies show that VSi(12)(-) adopts a V-centered hexagonal prism with a singlet spin state. The addition of the second V atom leads to a capped hexagonal antiprism for V(2)Si(12)(-) in a doublet spin state. Most interestingly, V(3)Si(12)(-) exhibits a ferrimagnetic, bicapped hexagonal antiprism wheel-like structure with a total spin of 4 μ(B).

Gold-doped germanium clusters, AuGen(-) (n = 2-12), were investigated by using anion photoelectron spectroscopy in combination with ab initio calculations. Their geometric structures were determined by comparison of the theoretical calculations with the experimental results. The results show that the most stable isomers of AuGen(-) with n = 2-10 are all exohedral structures with the Au atom capping the vertex, edge or face of Gen clusters, while AuGe11(-) is found to be the critical size of the endohedral structure. Interestingly, AuGe12(-) has an Ih symmetric icosahedral structure with the Au atom located at the center. The molecular orbital analysis of the AuGe12(-) cluster suggests that the interactions between the 5d orbitals of the Au atom and the 4s4p hybridized orbitals of the Ge atoms may stabilize the Ih symmetric icosahedral cage and promote the Au atom to be encapsulated in the cage of Ge12. The NICS(0) and NICS(1) values are calculated to be -143.7 ppm and -36.3 ppm, respectively, indicating that the icosahedral AuGe12(-) cluster is significantly aromatic.

Niobium-doped silicon clusters, NbSi (n = 3-12), were generated by laser vaporization and investigated by anion photoelectron spectroscopy. The structures and electronic properties of NbSi anions and their neutral counterparts were investigated with ab initio calculations and compared with the experimental results. It is found that the Nb atom in NbSi prefers to occupy the high coordination sites to form more Nb-Si bonds. The most stable structures of NbSi are all exohedral structures with the Nb atom face-capping the Si frameworks. At n = 8, both the anion and neutral adopt a boat-shaped structure and the openings of the boat-shaped structures remain unclosed in NbSi clusters. The most stable structure of the NbSi anion is endohedral, while that of neutral NbSi is exohedral. The global minima of both the NbSi anion and neutral NbSi are D symmetric hexagonal prisms with the Nb atom at the center. The perfect D symmetric hexagonal prism of NbSi is electronically stable as it obeys the 18-electron rule and has a shell-closed electronic structure with a large HOMO-LUMO gap of 2.70 eV. The molecular orbital analysis of NbSi suggests that the delocalized Nb-Si ligand interactions may contribute to the stability of the D symmetric hexagonal prism. The AdNDP analysis shows that the delocalized 2c-2e Si-Si bonds and multicenter-2e NbSi bonds are important for the structural stability of the NbSi anion.

Vanadium-doped silicon cluster anions, V 3 Si n − (n = 3−14), have been generated by laser vaporization and investigated by anion photoelectron spectroscopy. The vertical detachment energies (VDEs) and adiabatic detachment energies (ADEs) of these clusters were obtained. Meanwhile, genetic algorithm (GA) combined with density functional theory (DFT) calculations are employed to determine their groundstate structures systematically. Excellent agreement is found between theory and experiment. Among the V 3 Si n − clusters, V 3 Si 5 − , V 3 Si 9 − , and V 3 Si 12 − are relatively more stable. Generally speaking, three V atoms prefer to stay close with others and form strong V−V bonds. Starting from V 3 Si 11 − , cage configurations with one interior V atom emerge.

We present a combined experimental and theoretical study of ruthenium doped germanium clusters, RuGen− (n = 3–12), and their corresponding neutral species. Photoelectron spectra of RuGen− clusters are measured at 266 nm. The vertical detachment energies (VDEs) and adiabatic detachment energies (ADEs) are obtained. Unbiased CALYPSO structure searches confirm the low-lying structures of anionic and neutral ruthenium doped germanium clusters in the size range of 3 ≤ n ≤ 12. Subsequent geometry optimizations using density functional theory (DFT) at PW91/LANL2DZ level are carried out to determine the relative stability and electronic properties of ruthenium doped germanium clusters. It is found that most of the anionic and neutral clusters have very similar global features. Although the global minimum structures of the anionic and neutral clusters are different, their respective geometries are observed as the low-lying isomers in either case. In addition, for n > 8, the Ru atom in RuGen−/0 clusters is absorbed endohedrally in the Ge cage. The theoretically predicted vertical and adiabatic detachment energies are in good agreement with the experimental measurements. The excellent agreement between DFT calculations and experiment enables a comprehensive evaluation of the geometrical and electronic structures of ruthenium doped germanium clusters.

AuSi n – (n = 4–12) clusters were produced with a laser vaporization source and investigated by photoelectron spectroscopy. The swarm-intelligence-based CALYPSO structure search method and ab initio calculations were employed to determine their ground-state structures. The results revealed that the most stable isomers of AuSi n – (n = 4–12) cluster anions are all exohedral structures, in which the Au atom caps the vertex, edge, or surface of the bare Si n clusters. The endohedral and exohedral structures of neutral AuSi11 are nearly degenerate in energy. The most stable structure of neutral AuSi12 is endohedral. The growth mechanism of AuSi n – cluster anions is compared with those of AuGe n –, AgSi n –, and CuSi n – clusters. It implies that the bond strengths of Au–Si and Au–Ge play important roles in the formation of cage structures for AuSi12 – and AuGe12 –, while the different atomic radii of coinage metals, different bond strengths, and the strong relativistic effect in Au atom are responsible for the different growth mechanisms of Si clusters doped with different coinage metals.

We measured the photoelectron spectra of Nb2Si n – (n = 2–12) anions and investigated the geometric structures and electronic properties of Nb2Si n – anions and their neutral counterparts with ab initio calculations. The most stable structures of Nb2Si n – /0 (n = 2–12) clusters can be regarded as a central axis of Nb2 surrounded by the Si atoms. The most stable isomers of Nb2Si n – anions are in spin doublet states, while those of the neutral clusters are in spin singlet states. The results showed that the two Nb atoms in Nb2Si n – /0 clusters incline to form a strong Nb–Nb bond and also prefer to occupy the high coordination sites to form more Nb–Si bonds. The most stable isomers of anionic and neutral Nb2Si3 are D 3h -symmetric trigonal bipyramid structures, and that of Nb2Si6 – has C 2h symmetry with the six Si atoms forming a chair-shaped structure. The ground state structure of the Nb2Si12 – anion is a C 6v -symmetric capped hexagonal antiprism in which one Nb atom is encapsulated inside the Si12 cage and the second Nb atom caps the top of the hexagonal antiprism. It is found that the atomic dipole moment-corrected Hirshfeld population (ADCH) charge distributions on the two Nb atoms not only depend on the electronegativities of Si and Nb atoms but also relate with the structural evolution of Nb2Si n – clusters. The molecular orbital analyses of Nb2Si3 –, Nb2Si6 –, and Nb2Si12 – anions indicate that the delocalized Nb2–Si n ligand interactions and the strong Nb–Nb bonds play important roles in their structural stability.

The structural, electronic and magnetic properties of dual Cr atoms doped germanium anionic clusters, [Formula: see text] (n  =  3-14), have been investigated by using photoelectron spectroscopy in combination with density-functional theory calculations. The low-lying structures of [Formula: see text] are determined by DFT based genetic algorithm optimization. For [Formula: see text] with n  ⩽  8, the structures are bipyramid-based geometries, while [Formula: see text] cluster has an opening cage-like structure, and the half-encapsulated structure is gradually covered by the additional Ge atoms to form closed-cage configuration with one Cr atom interior for n  =  10 to 14. Meanwhile, the two Cr atoms in [Formula: see text] clusters tend to form a Cr-Cr bond rather than be separated. Interestingly, the magnetic moment of all the anionic clusters considered is 1 μ . Almost all clusters exhibit antiferromagnetic Cr-Cr coupling, except for two clusters, [Formula: see text] and [Formula: see text]. To our knowledge, the [Formula: see text] cluster is the first kind of transition-metal doped semiconductor clusters that exhibit relatively stable antiferromagnetism within a wide size range. The experimental/theoretical results suggest high potential to modify the magnetic behavior of semiconductor clusters through introducing different transition-metal dopant atoms.