Density‐functional thermochemistry. IV. 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 all 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.