Probing the structural evolution, electronic and vibrational properties of neutral and anionic potassium-doped magnesium clusters
Kai Ge Cheng, Dian Xing Song, Hai Hou, Yu Gao, Miao Cao, Jin Chan Wang, Xin Yu Li, Yaru Zhao
Abstract
• The most stable structures of the KMg n 0/– ( n = 2–12) clusters are determined. • The evolution of the structure and stability has be elucidated. • Two structures, KMg 9 and KMg 9 – , are uncovered and proved to be the magic number clusters with prominent stability. • The electronic and vibrational properties as well as bonding nature are discussed. Geometries, stabilities, bonding nature, and vibrational properties of bimetallic KMg n 0/– ( n = 2–12) clusters have been comprehensively studied by CALYPSO code within DFT calculations. The results reveal the structural transition from 2D to 3D at n = 3. From n ≥ 8, the geometry of KMg n 0/– transfers a hollow framework with a six-atom triangular prism unit. By comparing the geometry of neutral and anionic KMg n 0/– clusters, most of them are structurally different. In all doped clusters, the K atoms tend to localize on the convex positions of the skeleton and play the role of electron donors. Two highly stable clusters KMg 9 and KMg 9 – have been found, and studies showed that the prominent stability benefits from their compact magnesium structural motifs and quasi-full/full shell electronic configurations. Additionally, bonding nature analysis reflects there is much weak K-Mg interaction than Mg-Mg interaction in the KMg 9 0/– clusters. The spectroscopic properties based on the PES, IR and Raman spectra have also been discussed.