Use of dispersion correction (D3) in HF calculations ...

[evgeniy]

Hello,

I have a question about the dispersion correction to be used for DFT calculations, in particular D3.
I wonder if one can use it directly in HF calculations? I would appreciate if someone who tried that
gives his/her comments concerning the results obtained.
Many thanks!

Best regards,
Evgeniy

[Arnim]

Hi Evgeniy,

technically, this is not a problem. 
Just set up your HF calculation and switch in dispersion in define (or add '$disp3 bj' to control).
In the output you can see that the HF parameter are in such lines:
"
           DFT-D V3(BJ)
 DF hf                                               
 parameters
 s6       :    1.0000
 s8       :    0.9171
 a1       :    0.3385
 a2       :    2.8830  "

Since TM 7.0, you can also use the HF-3c approach (parameterized in connection with the minix basis set) by Sure and Grimme, if you add this control:
$disp3 bj func hf-3c

Cheers,
Arnim

[evgeniy]

Thanks a lot!