Assessment of exchange correlation functionals

We have examined the predictions of many of the generalised gradient approximation, and hybrid functionals, which are presently in the literature. Specifically we have looked at energetics and structures for two molecular sets, one with 93 systems and one with 147 systems. We find that recently developed functionals with more adjustable parameters give improved predictions when compared with less flexible functionals. (C) 2000 Elsevier Science B.V. All rights reserved.