Ab initio methods for reactive potential surfaces

Case studies of ten reactions using a variety of standard electronic structure methods are presented. These case studies are used to illustrate the usefulness and shortcomings of these standard methods for various classes of reactions. Limited comparisons with experiment are made. The reactions studied include four radical-radical combinations, H + CH3 -> CH4, CH3 + CH3 C2H3 H + HCO H2CO and CH3 + HCO -> CH3CHO, three abstraction reactions, H + HO2 -> H-2 + O-2,O- H + HCO H-2 + CO and CH3 + HCO CH4 + CO, a radical-inolecule addition, H + HCCH -> C2H3, and two molecular decompositions, H2CO -> H-2 + CO and CH3CHO -> CH4 + CO. The electronic structure methods used are DFT, MP2, CCSD(T), QCISD(T), CASSCF, CASPT2, and CAS + 1 + 2 + QC.