Relative Energy Computations with Approximate Density Functional Theory-A Caveat!

摘要

Approximate density functional theory (DFT) is now a common computational chemistry tool to examine a broad variety of structures and reactions involving increasingly larger molecules.DFT performs exceptionally well for molecular structures with much reduced computational effort than traditional ab initio methods,which it is often on par with,especially for difficult electronic situations-although this is not to say that right answers are given for the right reasons.While it has long been recognized and appreciated that there is no obvious way to improve DFT systematically,and although it is considered an approximate (short of saying empirical) method within its current implementations,it is silently assumed that the lack of quantitative accuracy is by far outweighed by the high qualitative agreement of structures and energies computed with this method.