The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 20 2 2020 08 22 Structural and electronic properties of Gen and EuGen-1 nanoclusters: A full potential DFT study Structural and electronic properties of Gen and EuGen-1 nanoclusters: A full potential DFT study 343 353 1621 10.47176/ijpr.20.2.21001 FA F Bamdadi 1. Department of Chemistry, Payame Noor University, Tehran, Iran ّF Abyar 2. Department of Chemical Engineering, Faculty of Engineering, Ardakan University, Ardakan, Iran R Behjatmanesh-Ardakani 1. Department of Chemistry, Payame Noor University, Tehran, Iran Journal Article 2020 02 05 In this work, the stability, structure and electronic properties of the nanoclusters of germanium (Ge<sub>n</sub>) and europium atom doped germanium clusters (EuGe<sub>n-1</sub>) with n=2 to 12, 15 and 20 were investigated. First, the stability of nanoclusters such as Ge<sub>n</sub> and EuGe<sub>n-1 </sub>was addressed using FHI-aims as a software package based on the density functional theory. Then the lowest-energy structures were selected for calculating  the first vertical ionization with the symmetry adapted cluster-configuration interaction General-R (SAC-CI-General-R) method. The results of this research show that there is a good agreement between calculation and experiment ionization potential for Ge<sub>n </sub>nanoclusters. Generally, the analyses of binding energies show that increasing the size of nanoclusters leads to more stability for nanoclusters. The most stable nanoclusters for EuGe<sub>n </sub>can be created with exchanging the Eu atom in the most stable Ge<sub>n+1 </sub>nanoclusters, but there is an exception for n=11 case. Here,  the second difference in energy (∆<sub>2</sub>E) and gap energy are computed for the stable nanoclusters. The results of ionization energy and second difference in energy confirm that Ge<sub>7 </sub>and Ge<sub>10</sub> also EuGe<sub>8 </sub>and EuGe<sub>10</sub> have the most stability. In this work, the stability, structure and electronic properties of the nanoclusters of germanium (Ge<sub>n</sub>) and europium atom doped germanium clusters (EuGe<sub>n-1</sub>) with n=2 to 12, 15 and 20 were investigated. First, the stability of nanoclusters such as Ge<sub>n</sub> and EuGe<sub>n-1 </sub>was addressed using FHI-aims as a software package based on the density functional theory. Then the lowest-energy structures were selected for calculating  the first vertical ionization with the symmetry adapted cluster-configuration interaction General-R (SAC-CI-General-R) method. The results of this research show that there is a good agreement between calculation and experiment ionization potential for Ge<sub>n </sub>nanoclusters. Generally, the analyses of binding energies show that increasing the size of nanoclusters leads to more stability for nanoclusters. The most stable nanoclusters for EuGe<sub>n </sub>can be created with exchanging the Eu atom in the most stable Ge<sub>n+1 </sub>nanoclusters, but there is an exception for n=11 case. Here,  the second difference in energy (∆<sub>2</sub>E) and gap energy are computed for the stable nanoclusters. The results of ionization energy and second difference in energy confirm that Ge<sub>7 </sub>and Ge<sub>10</sub> also EuGe<sub>8 </sub>and EuGe<sub>10</sub> have the most stability. germanium nanoclusters fhi-aims full potential first ionization energy second difference in energy gap energy https://ijpr.iut.ac.ir/article_1621_4462bf0ddbe0d0da40e1e828ebebeb11.pdf