The structure and dynamics of small microclusters are reported. Simulated annealing is used to find the global minimum energy structures of rare gas clusters modeled with a Lennard-Jones potential. The trends in the stability of these global minima generally correspond to those of experiment. Simulated annealing is also used to study the structure and stability of Lennard-Jones clusters with a variable strength three-body Axilrod-Teller term. The dimension and relative stabilities of the global minimum energy structures change with the increase of the strength of the Axilrod-Teller term. The structures change from three dimensional to two dimensional and then to one dimensional structures. The finite temperature lattice-based Monte Carlo method is proposed for determining the global minimum energy structures of heterogeneous clusters composed of similar type atoms and it is used to study the structure and relative stability of 7, 13, and 19 atom mixed argon and xenon rare gas clusters. / Molecular dynamics with quenching is used to study the dynamics of the 7 and 13 atom mixed cluster series. The phase transition temperature for the 7 atom mixed clusters show a plateau in the region around where the number of argon and xenon atoms are nearly equal. At a temperature slightly higher than the phase transition temperature, the octahedral + 1 based minima are the major pathways between the other minima. The barrier heights from the calculated transition states on the Ar$\sb7$ potential energy surface correlate to the results from the molecular dynamics calculations for the number of observed transitions between minima. The barrier heights from the global minimum to the next accessible minimum for the 7 atom mixed clusters correlates to the phase transition temperature in the molecular dynamics calculations. Finally, molecular dynamics calculations are performed on the 13 atom mixed cluster series and the phase transition temperatures show a plateau similar to the 7 atom results obtained for this system. The width of the plateau in the average kinetic energy versus the total temperature crudely correlates to the energy gap between the global minimum energy and the next highest accessible minimum energy. / Source: Dissertation Abstracts International, Volume: 51-07, Section: B, page: 3398. / Major Professor: Robert L. Fulton. / Thesis (Ph.D.)--The Florida State University, 1990.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_78281 |
| Contributors | Robertson, Daniel Harvey., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 151 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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