https://doi.org/10.1140/epjp/s13360-020-00745-6
Regular Article
Structures, stabilities and electronic properties of TimSin− (m = 1‒2, n = 14‒20) clusters: a combined ab initio and experimental study
1
Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, 116024, Dalian, China
2
School of Ocean Science and Technology, Dalian University of Technology, Panjin Campus, 124221, Panjin, China
3
Tianjin International Center of Nanoparticles and Nanosystem, Tianjin University, 300072, Tianjin, China
4
Department of Physics and FMF, University of Freiburg, 79104, Freiburg, Germany
Received:
9
July
2020
Accepted:
2
September
2020
Published online:
16
September
2020
Titanium-doped silicon clusters anions, TimSin− (m = 1‒2, n = 14‒20), have been investigated by photoelectron spectroscopy and density functional theory (DFT) calculations. Low-energy structures of TimSin− clusters have been globally searched using a genetic algorithm combined with DFT calculations. The electronic density of states and vertical detachment energies have been computed at the HSE06/aug-cc-pVDZ level and compared to the experimental data. Excellent agreement is found between theory and experiment especially in case of the singly doped clusters. In general, clusters with size m + n ≤ 17 prefer cage structures, while larger sized clusters evolve on a quasi-fullerene Ti@Si14 structural motif. Natural population analysis reveals that the Ti atoms possess negative charges and thus act as electron acceptors. The calculated binding energies and HOMO–LUMO gaps show that the clusters with cage structures have significantly higher stability, particularly Ti1Si16− and Ti2Si15−. One reason is that neutral Ti2Si15 exhibits a closed-shell electronic structure as a superatom, like Ti1Si16.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2020
