TY - THES
T1 - Theoretical studies of properties of clusters
A1 - Rehman,Habib ur
Y1 - 2008/07/28
N2 - This work is based on the calculation of total-energy minimum structures for various cluster systems using Density-Functional Tight Binding Method combined with genetic algorithm method. Cluster systems which we have investigated include both semiconductors and metallic clusters. Results of theoretical studies of binary SiGe clusters indicate the formation of mixed alloy structures for these clusters. We observe mostly heteroatomic bonds and there are fewer Si-Si bonds as compared to Ge-Ge bonds in binary clusters. We have calculated the bond energies for Si-Si bond, Ge-Ge bond and Si-Ge bond which also favour the formation of more heteroatomic and Ge-Ge bonds. In these binary clusters, Si shows very poor tendency to be coordinated with other Si atoms. In general % coordination of Si decreases from 5, as in pure Si clusters to 3 in binary SiGe clusters where as for Ge it increases from 3, as in pure Ge clusters to 5 in binary SiGe clusters. We also observed that binary SiGe clusters follow different growth pattern as compared to their elemental counter parts. Our observation is clearly depicted in similarity function analysis between these cluster systems.
In the second part of our work, we have studied the global energy minimum structures and structural and electronic properties of pure Copper clusters in the size range up to 36 atoms. We have used various descriptors for analysing the Cu clusters. We have obtained very symmetric Cu cluster structures in the size range less than 10.
KW - Cluster
KW - Dichtefunktionalformalismus
KW - Clusterverbindungen
CY - Saarbrücken
PB - Saarländische Universitäts- und Landesbibliothek
AD - Postfach 151141, 66041 Saarbrücken
UR - http://scidok.sulb.uni-saarland.de/volltexte/2008/1613
ER -