I. Astrophysical Observations and Models -- Molecular Astrophysics -- Chemical Composition and Molecular Abundances of Molecular Clouds -- Radio Observations of Interstellar Molecules -- Sub-Millimeter Astronomy and Astrophysics -- Infrared Spectroscopy of Interstellar Molecules -- Visible and Ultraviolet Studies of Interstellar Molecules -- The Production of Complex Molecules in Dense Interstellar Clouds -- Chemical Reactions in Diffuse Clouds and the Chemistry of Isotope Fractionation in the Interstellar Gas -- The Chemistry of Shocked Regions of the Interstellar Gas -- Theoretical Models of Shock Waves in Molecular Clouds -- Cometary Comae -- Molecular Spectra of the Outer Planets and Satellites -- II. Theoretical and Experimental Laboratory Studies -- Molecular Ions in Astrophysics and in the Laboratory -- Millimeter and Sub-Millimeter Wave Spectroscopy in the Laboratory and in the Interstellar Medium -- Studies of Astrophysically Important Molecular Ions with Ultrasensitive Infrared Laser Techniques -- Time Resolved Properties of Small Astrophysical Molecules -- Rotational Excitation in Molecular Beam Experiments -- Ion-Molecule Reactions at Low Temperatures -- Ion-Molecule Reactions in Interstellar Molecular Clouds -- Theoretical Predictions of the Infrared and Microwave Spectra of Small Molecules -- Recent Theoretical Results of Rotational-Translational Energy Transfer -- Rotational and Vibrational Energy Transfer in Diatomic and Polyatomic Molecules -- Calculation of Radiative Lifetimes of Allowed and Forbidden Transitions -- Molecular Photoionization Processes of Astrophysical and Aeronomical Interest -- Dissociative Recombination of Interstellar Ions: Electronic Structure Calculations for HCO+ -- Contributed Papers -- Detection of Interstellar Rotationally Excited CH -- Interstellar Clouds: From a Dynamical Perspective on their Chemistry -- Models of Galactic Molecular Sources -- Millimeter Wave Spectroscopy of Transient Species in RF and DC Discharges -- Photofragment Spectroscopy of Interstellar Molecules -- Measurements of Ion-Molecule Reaction Rate Coefficients between 8 and 160 K by the Cresu Technique -- Measurements of Ion-Molecule Reaction Rate Coefficients with an Ion-Drift-Tube Method at Temperatures from 18 to 420 K -- Laboratory Studies of Ion Reactions with Atomic Hydrogen -- Dissociative Recombination of H3+, HCO+. N2H+, and CH5+ -- Molecular Dissociation Functions Obtained from Thermodynamic and Spectroscopic Data -- A Theoretical Study of H2O Masers -- The Excitation of Interstellar C2 -- Photodissociation Processes in the OH and HC? Molecules -- Low Temperature Rosseland Mean Opacities for Zero-Metal Gas Mixtures -- Contributed Oral Presentations -- A High-Sensitivity Spectral Survey of Orion A in the 1.3 MM Region -- The Importance of Neutral-Neutral Reactions in the Chemistry of CN in Diffuse Clouds -- Long Chain Molecules in Interstellar Clouds -- Desorption of Molecules from Interstellar Grains -- Molecular Mantles on Interstellar Grains -- Electron Capture by Multiply Charged Ions: Population of Excited States -- Photoabsorption and Photodissociation of CO in the 900-1200 A Region -- Photodissociation of H2O in the First Absorption Band in the VUV as the Pumpmechanism of the Astronomical OH-Maser -- Laser Spectroscopy on Small Molecules of Astrophysical Interest in the Vacuum UV -- Experimental Measurements of the Branching Ratio for Dissociative Recombination Processes -- Astrophysically Important Charge Transfer Reactions: Recent Theoretical Results -- Potential Surface of C2-H2 -- Theoretical Predictions of Atomic and Molecular Properties for the Construction of Empirical Scattering Potentials -- Rovibrational Excitation of 12C16O by H2 -- List of Participants -- Molecule Index.