OICC Press Journal of Theoretical and Applied Physics 2251-7235 6 1 2023 11 17 Density functional investigation of structures and energetics of pure and Sn-doped small lithium clusters 10.1186/2251-7235-6-18 EN Masoud Ansarino Department of Physics, South Tehran Branch, Islamic Azad University, Tehran, Iran 0000-0002-2311-5068 Shahab Zorriasatein Department of Physics, Faculty of Science, Islamic Azad University-South Tehran Branch, Tehran, Iran Journal Article 2023 11 17 AbstractGround state geometry, energetics, and bonding of pure Lin ( n = 2 – 9 ) and impureLinSn ( n = 1 – 8 ) small clusters are investigated using the density functional theory. Introducing a single Sn impurity significantly changes the geometry of the host clusters for n > 5. Although the Sn atom is not trapped inside the cluster, it has the greatest coordination number among other atoms in the cluster. The analyses showed that the nearest neighbor bond lengths in Sn are approximately 10% shorter than those in Li. The results elucidate that the binding energy per atom in impure clusters is greater than that in pure clusters. Finally, it is shown that for and Li8 and Li4Sn clusters that each have with eight valence electrons, the greater gap in the highest occupied molecular orbital and the lowest unoccupied molecular orbital results in a more stable cluster.