The efficiency of density functional theory has been much improved. In particular,
the density fitting (DF-RKS, DF-UKS) codes for analytical energy gradients are now
very much faster, due to a new integral code (adaptive integral core, AIC) written by G. Knizia.
Some benchmarks can be found in H.-J. Werner, P. J. Knowles, G. Knizia, F. R. Manby, and M. Schütz,
*Molpro - a general purpose quantum chemistry program package*,
WIRES Comput. Mol. Sci. **2**, 242 (2012).

molpro@molpro.net 2019-02-23