Probing the properties of size dependence and correlation for tantalum clusters: geometry, stability, vibrational spectra, magnetism, and electronic structure

Abstract

A comprehensive investigation on the equilibrium geometry, relative stability, vibrational spectra, and magnetic and electronic properties of neutral tantalum clusters (Ta n , n ¼ 2-17) was performed using density functional theory (DFT). We perform a study of the size dependence and correlations among those descriptors of parameters, and showed these could provide a novel way to confirm and predict experimental results. Some new isomer configurations that have never been reported before for tantalum clusters were found. The growth behaviors revealed that a compact geometrical growth route is preferred and develops a body-centered-cubic (BCC) structure with the cluster size increasing. The perfectly fitted functional curve, strong linear evolution, and obvious odd-even oscillation behavior proved their corresponding properties depended on the cluster size. Multiple demonstrations of the magic number were confirmed through the correlated relationships with the relative stability, including the second difference in energy, maximum hardness, and minimum polarizability. An inverse evolution trend between the energy gap and electric dipole moment and strong linear correlation between ionization potentials and polarizability indicated the strong correlation between the magnetic and electronic properties. Vibrational spectroscopy as a fingerprint was used to distinguish the ground state among the competitive geometrical isomers close in energy. The charge density difference isosurface, density of states, and molecular orbitals of selected representative clusters were analyzed to investigate the difference and evolutional trend of the relative stability and electronic structure. In addition, we first calculated the ionization potential and magnetic moment and compared these with the current available experimental data for tantalum clusters. † Electronic supplementary information (ESI) available: The computational details including DFT method, denition of reactivity descriptors, and nite eld treatment method; the analysis of geometrical isomers and their energy difference; the calculated parameters of neutral Ta n (n ¼ 2-17) clusters for all relative stable geometrical isomers (Table S1); the DOS of representative Ta n (n ¼ 7, 10, 13 and 15) clusters (Fig. S1). See

Structures of Small Tantalum Cluster Anions: Experiment and Theory

“…The structures of Ta 13 and Pt 13 were analyzed in detail by Zhang et al, also by PAW methods . Li et al looked at the structures and properties of Ta n ( n = 2–17) by a DFT method . DFT was also used by Du et al for Ta n + clusters with n = 6–16.…”

“…25 Li et al looked at the structures and properties of Ta n (n = 2−17) by a DFT method. 26 DFT was also used by Du et al 27 IRMPD data of ref 8. Finally the electronic structure and properties of the isomers of Ta 12 2+ were computed by Du et al 28 We are not aware of any systematic study on Ta cluster anions.…”

An Open-Shell Superatom Cluster Ta10– with Enhanced Stability by United d–d π Bonds and d-Orbital Superatomic States

“…We then compared the structures and energetics of the Ta n – ( n = 3–15) clusters, as shown in Figure . The structures and electronic states of these tantalum clusters were optimized with the initial structures from the literature. − Among them, Ta 10 – and Ta 12 – have hollow-sphere-like structures, while Ta 14 – and Ta 13 – display core–shell structures. Interestingly, Ta 3 – , Ta 5 – , Ta 7 – , and Ta 11 – are triplets in their ground states, whereas the lowest-energy structures for all of the other clusters correspond to low-spin states.…”