Density-functional thermochemistry .4. A new dynamical correlation functional and implications for exact-exchange mixing

A new dynamical correlation functional is constructed subject to a small number of simple, yet key, requirements not ail satisfied by existing functionals in the literature. The new functional gives good atomic correlation energies, and, in conjunction with previous gradient-corrected exchange functionals and exact:exchange mixing, excellent thermochemistry in the G2 benchmarks of Pople and co-workers. (C) 1996 American Institute of Physics.