Discovery and characterization of novel molecular species important to fundamental and applied problems in physics, chemistry and astrophysics: The transition from molecular to bulk properties in materials, identification of interstellar and circumstellar molecules and molecular precursors to life in space, applications in semiconductor fabrication and fuel combustion. Experimental techniques include Fourier transform spectroscopy, laser ablation of solids, low temperature spectroscopy and high vacuum techniques. A critical step is testing experimental conclusions about molecular spectra and structures against the predictions of density functional theory (DFT) calculations.