Scientific Research Division

    Research interests of the molecular science group encompass the whole gamut of photochemical and photophysical processes, from photoabsorption, photoionization, photodissociation, to Auger electron emission, of gas-phase atoms and molecules and condensed-phase molecules and materials exposed to photons with energies ranging from ultraviolet to soft X-rays. The choices of the samples are dictated either by their merits in revealing important photochemical or photophysical properties, or by their relevance to atmospheric chemistry, astrochemistry, and combustion chemistry. Experimental techniques include precision photoabsorption of isotopomers, photoelectron spectroscopy, Auger electron (or core-level excitation) spectroscopy, photoionization mass spectrometry, matrix-isolation Fourier-transform-infrared spectroscopy (MI-FTIRS), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), crossed-molecular-beam time-of-flight mass spectrometry (CMB-TOF-MS), and various laser-synchrotron combination techniques. Data derived from the assorted experimental approaches are geared toward revealing the structures, energetics, decay hierarchies, formation mechanisms, and reaction dynamics of various neutral and ionic atoms and molecules. For instance, MI-FTIRS can probe transient species synthesized from precursors excited with photons or electrons, MALDI-TOF-MS can explore the structures of biomolecules by selective core-level excitation, and CMB-TOF-MS can unravel the mechanisms and dynamics of elementary chemical reactions.