Extracting Thermochemical Information from ab Initio Data

Who needs ab initio data?

Who believes ab initio data?

Dramatic decline in cost

Theory with experiment

Superficial overview of quantum chemistry

MO theory: Hartree-Fock

Basis sets

MO theory: electron correlation

Popular correlated methods

Semiempirical MO theory

Multiconfiguration methods

Density functional theory

Problems to beware when reading or doing

Popular composite methods

Basis set extrapolation Error in De(H2) (kJ/mol)

G2 family of methods

CBS family of methods

SAC/PCI family of methods

BAC-MP4 method

Bond strength error vs. bond length