this is impossible to do with Firefly version 7.1.G.
However, the forthcoming version 7.1.H allows one to change
the fraction of HF exchange used in any supported hybrid
functional. This was done primary as a tool for stabilization
graphs based approaches, e.g., to identify and track CT and
I can provide you the latest development binaries -
please contact me directly if you are interested.
Another point is that P86 correlation functional is not
implemented so you will need to try some alternatives
e.g. PBE96 correlation.
On Mon Jun 21 '10 6:11pm, Miro Moman wrote
>I am modelling an iron-sulfur cluster. To the best of my knowledge, Szilagyi and Winslow (J. Comput. Chem. 2006, 27, 1385-1397) have carried out the most systematic optimisation of DFT functionals for this kind of systems to date.
>They recommend using a hybrid functional with 5% HF exchange and 95% density functional exchange supplemented with Perdew's 1986 correlation functional. Can I implement this in Firefly? Which keywords should I use?
>If defining custom functionals is not possible, which of the available functionals would you recommend?