This research, part of the Experimental Physical Chemistry Program, utilizes the techniques of gas phase electron diffraction to elucidate the molecular structure of prototypical gas phase inorganic and organic species. These data are important for understanding chemical bonding, calculating thermodynamic properties and elucidating vibrational and rotational energy levels of these species. Among the problems to be studied are relative stabilities of rotational conformers, gaseous equilibria of both rotational conformers and monomer, dimer and larger species, rotational potentional functions and barriers to internal rotation, nature of bonding in transiton metal compounds, structures of small ring compounds with conjugated systems of bonds, and structures of gas phase high temperature inorganic materials.