The work presented in this thesis concerns the production of high-temperature spectroscopic line lists for the SO2 and SO3 molecules, for the purposes of astrophysical, terrestrial and industrial applications. Both line lists are computed using ab initio computational methods to calculate rovibrational energy levels and dipole moment transition intensities. The hot SO2 line list is computed usi...

Recent single-molecule experiments indicated that thioethers (dialkyl sulfides) on gold surfaces act as thermallyor mechanically activated molecular rotors, although the mechanisms for these phenomena are not yet clearly understood. Here we present theoretical and experimental investigations of the rotational dynamics of these thioether molecules. Single-molecule studies utilizing low-temperatu...

Theory is developed for the calculation of dipole transition line strengths and frequencies for rotational and ro-vibrational transitions from wavefunctions expressed in the generalized body-fixed co-ordinates proposed by Sutcliffe and Tennyson (1986, Molec. Phys., 58, 1053). Computations using this theory produce calculated frequencies for the fundamental ro-vibrational transitions of H2 D+ an...

The adsorption of molecular hydrogen on sulfurand chlorine-covered Pd(100) in a (2×2) geometry is studied by ab initio molecular dynamics simulations. The potential energy surfaces of H2/S(2 × 2)/Pd(100) and H2/Cl(2× 2)/Pd(100) are rather similar. Consequently, also the dependence of the sticking probability on incident kinetic energy, angle of incidence and internal excitations are very close....

Theory predicts the water hexamer to be the smallest water cluster with a three-dimensional hydrogen-bonding network as its minimum energy structure. There are several possible low-energy isomers, and calculations with different methods and basis sets assign them different relative stabilities. Previous experimental work has provided evidence for the cage, book, and cyclic isomers, but no exper...

Product state distributions of the CO produced in the 308-nm photolysis of acetaldehyde show clear evidence of two dissociation mechanisms. One is attributed to the conventional transition state mechanism predicted by theory, with high rotational and translational energy of the CO and a pronounced v(perpendicular)J vector correlation. However, as much as 15% of the reaction flux proceeds via an...