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.

The lasing characteristics and the spectroscopy of intramolecular proton transfer molecules have been investigated in nonpolar and polar solvents. In addition molecular orbital calculations on intramolecular proton transfer molecules have been performed. The efficient generation of coherent stimulated emission from 3-hydroxyflavone (3-HF) and fisetin, two molecules which exhibit intramolecular proton transfer has been shown. Amplified spontaneous emission from 3-HF is achieved in polar aprotic and moderately protic solvents. The observed shifts of the tautomer fluorescence are attributed to hydrogen bonding interactions with the solvent. In contrast 3-hydroxychromone does not exhibit amplified spontaneous emission in various solvents and concentrations. Picosecond transient absorption experiments reveal the existence of absorption bands overlapping the emission, which leads to high loss terms in the gain equation. The extensive aggregation of this molecule at high concentrations further lowers the gain coefficient for stimulated emission. 3-HF has been shown to form the anion in the ground state in formamide solutions. The distinct absorption, emission and transient absorption bands of the anion have been identified. The transient absorption bands of the neutral molecule are not affected by the polar environment. The risetime of the tautomer fluorescence is shown to be slowed by hydrogen bonding interference from the solvent. Ab initio calculations on 3-hydoxy-4-pyrone predict the possibility of intramolecular proton transfer in the excited state. The dipole moment values and the Mulliken population analysis are consistent with the proton transfer picture. INDO calculations on the same molecule show a discrepancy with the ab initio results. Benzanilide shows a very fast monoexponential rise of the tautomer fluorescence at room temperature. At 77 K the rise / becomes biexponential. The tautomer ground state transient absorption has been observed. The results are explained in terms of a double proton transfer mechanism resulting from dimer formation. Finally a supersonic molecular beam apparatus is described. / Source: Dissertation Abstracts International, Volume: 49-07, Section: B, page: 2671. / Major Professor: Michael Kasha. / Thesis (Ph.D.)--The Florida State University, 1988.

Source: Dissertation Abstracts International, Volume: 32-11, Section: B, page: 6332. / Thesis (Ph.D.)--The Florida State University, 1971.

Source: Dissertation Abstracts International, Volume: 32-11, Section: B, page: 6336. / Thesis (Ph.D.)--The Florida State University, 1971.

Source: Dissertation Abstracts International, Volume: 35-12, Section: B, page: 5838. / Thesis (Ph.D.)--The Florida State University, 1974.

Source: Dissertation Abstracts International, Volume: 36-01, Section: B, page: 0259. / Thesis (Ph.D.)--The Florida State University, 1975.

Source: Dissertation Abstracts International, Volume: 36-04, Section: B, page: 1731. / Thesis (Ph.D.)--The Florida State University, 1975.

Source: Dissertation Abstracts International, Volume: 36-08, Section: B, page: 3986. / Thesis (Ph.D.)--The Florida State University, 1975.

Source: Dissertation Abstracts International, Volume: 36-08, Section: B, page: 3990. / Thesis (Ph.D.)--The Florida State University, 1975.

Source: Dissertation Abstracts International, Volume: 36-08, Section: B, page: 3991. / Thesis (Ph.D.)--The Florida State University, 1975.