TURBOMOLE Users Forum

TURBOMOLE Modules => Ridft, Rdgrad, Dscf, Grad => Topic started by: igor on August 13, 2008, 05:33:58 PM

Title: Help for Ex and Ec components seperately
Post by: igor on August 13, 2008, 05:33:58 PM
Hi everyone:
     Due to my project, I want to print the exchange and correlation energy in DFT seperately, but I don't know how to do.

     who can give me some advice?

     Thanks!
Title: Re: Help for Ex and Ec components seperately
Post by: uwe on September 22, 2008, 04:12:05 PM
Hi,

exchange and correlation are not calculated separately, so the energies are only available for the sum of all parts.

What you can do is to do single-point calculations with exchange and correlation functionals only - but this works only for those functionals where the X- or C-only functionals are accessible.

To check this, run define, enter the dft section in the last menu and enter func. You will get a list of available functionals.

E.g. b-lyp is available as well as becke-exchange as the exchange-only functional and lyp as the correlation-only functional.

So if you do a B-LYP calculation, copy the input to new directories, change $scfiterlimit to 1, and replace b-lyp by becke-exchange and lyp resp. Run single-point jobs and grep for "Exc =" in the outputs.

This will give at least an idea of the exchange and the correlation contribution to the energy of the functionals.

Regards,

Uwe