ENERGETICS USING DFT - COMPARISONS TO PRECISE ABINITIO AND EXPERIMENT

Density functional theory (DFT) has been used to analyze a large numbe r of small molecules and to assess the quality of the energies using l ocal and non-local functionals. The absolute DFT energies are compared to very precise ab initio results and the relative (atomization and d issociation) energies are compared to ab initio and experiment. The lo cal approximation yields very poor energies; nevertheless, the errors follow an interesting linear trend with respect to the total energies that provides a trivial way to get corrected results. The non-local pr ocedure used in this work yields acceptable energies and constitutes a very promising method for energetics studies.