Institute for Theoretical Atomic, Molecular and Optical Physics between AMO theory and experiment and promoting AMO theory within the general physics community. It has been involved in some capacity in most of the National Research Council target areas, i.e. precision measurements and tests of fundamental laws, ultracold physics, the development and application of ultra-intense, short wavelength light sources, ultra-fast quantum control of atoms, molecules and electrons, nanoscience, and quantum information science. The Institute is sponsored by the National Science Foundation, the Smithsonian Institution, the Center for Astrophysics and Harvard University. The Armstrong Report in 1987 on "The State of Theoretical Atomic, Molecular and Optical Sciences in the United
Atomic absorption spectroscopy band will overlap with an atomic line. This kind of absorption might be caused by un-dissociated molecules of concomitant elements of the sample or by flame gases. We have to distinguish between the spectra of di-atomic molecules, which exhibit a pronounced fine structure, and those of larger (usually tri-atomic) molecules that don’t show such fine structure. Another source of background absorption, particularly in ET AAS, is scattering of the primary radiation at particles that are generated in the atomization stage, when the matrix could not be removed sufficiently in the pyrolysis stage. All these phenomena, molecular absorption and radiation scattering,