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Can anyone help me to run a geometry optimization and frequency calculation using B2PLYP-D3 functional including the DFT-D3 dispersion correction? I went through Gaussian manual, however, it was not very clear to me. 

%NProcshared=4
%Mem=4gb
%chk=fohsdft3
# B3PLYP/aug-cc-pVDZ opt freq scf=tight

Input file taken from fohsdft

0 1
 O                  -3.46278   2.54045   0.                                
 H                  -2.50278   2.54045   0.                                 
 H                  -3.78324   3.44539   0.

We have the Gaussian 09 Revision C.01 version.

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    $\begingroup$ When I did B3LYP-D3 calculations on protein-ligand interactions in a course project about 5 months ago, I used the following keyword to enforce Grimme's D3 correction: EmpiricalDispersion=GD3. I was also confused about the manual, but here's how I interpreted the manual: "GD3 parameters are defined for the list of functionals in the table, and to invoke these use the keyword EmpiricalDispersion=GD3". This worked for me, but perhaps others can confirm. The manual I refer to is this page: gaussian.com/g_tech/g_ur/k_dft.htm $\endgroup$
    – Yoda
    May 31, 2016 at 9:44
  • $\begingroup$ Just a reminder that f you've found any of the answers as acceptable, please mark/accept it so that future users can benefit. $\endgroup$
    – pentavalentcarbon
    Jul 4, 2016 at 17:57

2 Answers 2

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Search for B2PLYP on the Moller-Plesset page:

B2PLYPD3 requests the same but with Grimme's D3BJ dispersion [Grimme11, Goerigk11].

The correct D3 parameters will be set for you automatically.

%nprocshared=4
%mem=4gb
%chk=fohsdft3
# opt freq b2plypd3/aug-cc-pvdz scf=tight

Input file taken from fohsdft

0 1
O                  -3.46278   2.54045   0.
H                  -2.50278   2.54045   0.
H                  -3.78324   3.44539   0.

Since B2PLYP-D3 is a method, it goes where the density functional is normally specified.

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As Yoda suggested, you have to include empircal dispersion as a keyword on the route section. That specifies you want to include dispersion effects in the calculation. You can just specify the B2PLYPD3 functional in your route section since it is parameterized with dispersion correction.

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