Computational Exploration on the Structural and Optical Properties of Gold-Doped Alkaline-Earth Magnesium AuMgn (n = 2–12) Nanoclusters: DFT Study

Density functional theory-based study on the structural, electronic and spectral properties of gas-phase PbMg n - (n = 2-12) clusters

Gas-phase PbMg n- (n = 2-12) cluster structures were globally searched on their potential energy surfaces by means of the CALYPSO prediction software. Structural optimization and calculations of properties such as relative energy and electronic structure were then carried out by density functional theory for each size of low energy isomer. The structural, relative stability, natural charge population, natural electronic configuration and distribution of the strongest peaks of the infrared and Raman spectra of the low energy isomers of PbMg n- (n = 2-12) clusters were systematically investigated in the present work. It was shown that the PbMg7- cluster ground state isomer exhibits the highest stability, for which special electronic excitation and chemical bonding analyses were performed. It is reasonable to believe that this work enriches the structural, spectroscopic and other data of magnesium-based clusters and provides some theoretical basis for possible future experimental syntheses.

Structural and spectral properties of Gas-phase FMgn (n = 2-20) clusters based on DFT

Structure, stability, electronic structure, spectroscopy and chemical bonding properties of a fluorine atom doped gas-phase small to medium-sized magnesium clusters, FMgn (n = 2-20), systematically investigated by CALYPSO software together with density functional theory (DFT). Structural calculations showed that FMgn has a structural diversity which is rarely reported in other magnesium-based clusters before. F atoms were always located in the outer layer of the Mgn host clusters and only two or three Mg atoms surround it. FMg18 was revealed to be supposed to have robust relative stability. Charge transfer and density of states were calculated for analyzing the electronic structure characteristics. Theoretical calculations of IR, Raman and UV-Vis spectra were computed to provide data guidelines for future experimental observations. Finally, the F-Mg and Mg-Mg chemical bonds of the FMgn clusters were analyzed, including the critical bonding points (BCPs) of Laplacian of electron density (Δρ), electron localization function (ELF) and interaction region indicator (IRI). The kind and strength of chemical bonds reveal the mechanism by which the F atom was rapidly stabilized by Mgn (n = 2-20) host clusters.

Growth pattern and electronic and magnetic properties of Cr-doped silver clusters

Growth pattern and electronic and magnetic properties of Agn Cr (n = 1-16) clusters have been investigated via density functional theory (DFT) combined with CALYPSO structure search method. The optimized geometry shows that the growth of the global minimum structures of Agn Cr clusters have obvious rule. when n > 12, silver atoms grow around an icosahedron which is almost unchanged in each structure. Analyses of electronic properties indicate that the doped Cr atom can only enhance the stability of larger silver clusters. Optical absorption and photoelectron spectra of Agn Cr isomers have been predicted and can be used for their structural identification. The icosahedral Ag12 Cr cluster with large energy level gap can be seen as a superatom. The adsorption capacity of Cr atom in Agn Cr cluster to CO is much higher than that of free Cr atom. The intensity of IR and Ramam spectra can be dramatically enhanced when CO is absorbed on Agn Cr cluster that Cr atom is encapsulated by Ag atoms. Moreover, the red shift of IR and Raman spectra of CO adsorbed on these clusters is also very small compared to free CO. Magnetism calculations show that the magnetic moment of Agn Cr clusters decreases linearly from n = 6 to 12 and increases linearly from n = 12 to 16. The total magnetic moment of Agn Cr cluster is mainly localized on the Cr atom. The change of magnetic moment of Cr atom is related to the charge transfer between Cr and Ag atoms.