Structural Evolution of Tc sub(n) (n = 4-20) Clusters from First-Principles Global Minimization

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 119; no. 33; pp. 8892 - 8897
• Main Authors: Priest, Chad, Tang, Qing, Jiang, De-en
• Format: Journal Article
• Language: English
• Published: 01.08.2015
• Subjects: Clusters; Corners; Density functional theory; Evolution; Minimization; Optimization; Stability; Symmetry
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/acs.jpca.5b04015

We explore the structural evolution of Tc sub(n) (n = 4-20) clusters using a first-principles global minimization technique, namely, basin-hopping from density functional theory geometry optimization (BH-DFT). Significantly more stable structures have been found in comparison with previous models, indicating the power of DFT-based basin hopping in finding new structures for clusters. The growth sequence and pattern for n from 4 to 20 are analyzed from the perspective of geometric shell formation. The binding energy per atom, relative stability, and magnetic moments are examined as a function of the cluster size. Several magic sizes of higher stability and symmetry are discovered. In particular, we find that Tc sub(19) prefers an O sub(h) symmetry structure, resembling a piece of a face-centered-cubic metal, and its electrostatic potential map shows interesting features that indicate special reactivity of the corner atoms.