How to run a B2PLYP-D3 calculation in Gaussian 09? 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.
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.