Theoretical Background of Heterogeneous Catalysis.- Analysis of CO-Metal Cluster Interaction Energies by the Hartree-Fock-Slater Method.- Chemisorption Properties of Transition Metal Clusters.- Gas, Organic Solid State Reactions and Their Applications.- Some Theoretical Questions Concerning the Mechanism of Fischer-Tropsch Synthesis.- Environmental Effects on Proton Transfer. Ab Initio Calculations on Systems in a Semi-classical, Polarizable Environment.- Recent Quantum/Statistical Mechanical Studies on Enzyme Activity Serine Proteases and Alcohol Dehydrogenases.- Applications of Quantum Chemistry to Pharmacology.- On the Pharmacophore and Mode of Action of Some Schistosomicidal Agents. Conformational Aspect.- Intermolecular Interactions and Solvent Effects: Simplified Theoretical Methods.