Physics and Astronomy
Permanent URI for this collection
Browse
Browsing Physics and Astronomy by Author "Dhillon, Harneet Kaur"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
Item Open Access Trends in Geometry and Energy of Metal and Metal Oxide Clusters Calculated by Density Functional Theory(2020-08-11) Dhillon, Harneet Kaur; Fournier, Rene AndreWe have studied the structural and electronic properties for different groups of atomic clusters by doing a global search on the potential energy surface using a modified version of the Tabu search in descriptor space method. The geometry optimizations and calculation of energies were carried out using Density Functional Theory implemented in the Gaussian 09 and Gaussian 16 software. For Agn, (n = 420), AgnCl2, (n = 310,12) and AgnHgm, (n = 5,6 and m = 1 4) clusters, we have found that the change from planar to 3 dimensional geometry occurs at cluster size n > 6. Binding of Cl atoms to Ag atoms causes greater distortion in shape as compared to binding of Hg atoms to Ag atoms. For Li, Mg, Al clusters, we studied 130 binary and ternary clusters such that AmBn (5 m+n 8) with A,B = Li,Mg,Al and ApBqCr (5 p + q + r 8), with A,B,C = Li,Mg,Al. We analyzed trends in atomization energies with a sequence of linear regressions of increasing complexity. For AlxOy, (x + y < 17) clusters, the most stable cluster is non-stoichiometric(x/y = 2/3); Al6O8. Analysis of relative stability and energies of reaction for AlxOy clusters suggests that non-stoichiometry could play a role in early stages of growth of group 13 oxides. The structures for most stable clusters for SixOy, (x = 14), (y = 2x,2x1) and Si3Oy,(y = 19) clusters are diverse and do not follow a simple growth principle. We analyzed the geometry, asphericity and shape descriptors for metal oxides (MxOy) such that (x + y 12), where M= Li, Mg, K, Zn, Cu, Ag, Si, and Al. This analysis suggests a preference for prolate geometries for (SiO)n clusters, oblate geometries for (ZnO)n clusters and no obvious pattern in shape for all other clusters. In every case, the favored structures have very few M-M bonds and O-O bonds.