I was just asked if it is possible to perform DFT-D3 calculations in Gaussian and my first answer was to use the following keyword:
which is available in G16 and G09 only in revision D, apparently.
There are also some overlays that can be used to invoke the use dispersion in various scenarios:
IOp(3/74=x) Exchange and Correlation Potentials
|DSD-PBEP86 (double hybrid, DFT-D3).
B2PLYP-D3 (double hybrid, DFT-D3).
IOp(3/76=x) Mixing of HF and DFT.
|-33||PW6B95 and PW6B95-D3 coefficients.|
IOp(3/124=x) Empirical dispersion term.
|Force dispersion type 3 (Grimme DFT-D3).
Force dispersion type 4 (Grimme DFT-D3(BJ)).
Force dispersion type 5 (Grimme D3, PM7 version).
The D3 correction method of Grimme defines the van der Waals energy like:
where coefficients are adjusted depending on the geometry of atoms i and j. The damping D3 function for is:
where the values of s are adjustable parameters fit for the exchange-correlation functionals used in each calculation.
Very useful. Thank you so much.
how can apply Dispersion DFT-D2 in Gaussian 09?
In ORCA I can use HF with dispersion, is that also possible for G16?
It’s for a benchmark, don’t judge me 😉
No judgement here LOL I don’t see why not. If you have the latest G16 revision you might try with EmpiricalDispersion=GD3, but you can also go to Grimme’s webpage, load your file, select method = HF, and get the empirical dispersion added to your molecule (http://wwwtc.thch.uni-bonn.de/); not really useful for a benchmark, I know but is worth knowing it.
I hope this helps!
How to use dispersion correction in ONIOM?
The same way you use it in a regular calculation. You can also use one of the functionals already including it such as wB97XD
I hope this helps