Theoretical Exploration of Cluster Nanoarchitectonics: Effects of Doping a Ge13 Cluster with Ta, Fe, Pd, and Co through DFT

This article primarily explores the electronic properties and geometrical structures of a Ge 13 cluster with single-atom doped X (Ta, Fe, Pd and Co) based on density functional theory (DFT). The spin-polarized exchange correlation functional was used to analyze the isomers of doped Ge 12 X clusters generally to classify the stable structures. This work explores the diverse doping positions and magnetic parameters on each isomer. The analysis indicates that the Ta, Fe, Pd and Co doped Ge 12 X with cuboctahedral and decahedral structures have the lowest energy structures, whereas Ge 13 mainly favors a cuboctahedral structure. The different doping atom positions contribute to strengthening the stability of the Ge 12 X cluster structures. Moreover, the Bader charge analysis of doped Ge 1 2 X reveals −0.3e accumulated for the dopant Ta as an electron donor in the cluster while other dopants tend to accept the electrons and the HOMO–LUMO gap is notably reduced. Density of states (DOS) analysis indicates that doped Ge 12 X is semimetallic and is capable of holding magnetism. In general, this work summarizes the relevance of inserting the doped atom at a strategic position on the Ge 11 X 2 cluster in finding the stable structure.