Density Functional Theory Of Al_nCo^-（1≤n≤9） And C₂H₂N₂XY（X,Y=Se,Te） Clusters

The geometrical structures, relative electronic and magneticproperties of small AlnCo-(1≤n≤9) clusters have been investigatedsystematically within the framework of density-functional theory atthe BPW91level. Doping with a single Co can dramatically affect theground-state geometries of the Aln+1-clusters. At the same time, theresulting geometries show that the lowest energy AlnCo-clustersprefer to be three-dimensional structures. Here, the relativestabilities are investigated in terms of the calculated average bindingenergies, fragmentation energies, and second-order difference ofenergies. Moreover, the result of the highest occupied-lowestunoccupied molecular orbital energy gaps indicates that Al6Co-clusters has the highest chemical stability for AlnCo-(1≤n≤9)clusters. Furthermore, the natural population analysis reveals thatthe charges in AlnCo-clusters transfer from the Al frames to the Coatom. Additionally, the analyses of the local and total magnetic moments of AlnCo-clusters show that the magnetic influence mainlycome from the Co atom.Oxadiazole derivatives has many important properties such asanalgesic, anti-viral and anti-cancer activity, so this is especiallyimportant for the development of medicine and pharmacy. In thispaper, selenium tellurium replace Oxadiazolones sulfur and oxygenatoms in a single-structural isomers double tellurium analogues andtautomers (C2H2N2XY; X, Y=Te, Se) were studied. All of isomers andtautomers are used B3LYP method, for C, H, O, N atom usingaug-cc-pVDZ basis set, selenium and tellurium atoms with LANL2DZbasis set. We consider the structure of the four groups in each group30tautomer in a gaseous environment and IEF-PCM implicit waterenvironment. The calculated results of gibbs free energy suggest thattautomeric containing CH2groups are most unstable. Meanwhile thestructures which is formed by tellurium substituted ring oxygen atomare more stable than selenium substituted with the ones. To someextent, this is probably mainly due to the large radius of telluriumatom and small tension ring.