Mod:Hunt Research Group:multiwfn mp2 density

Using MP2 Densities in Surface Analysis with Multiwfn

• for a system at the MP2 (or other non-HF, non-DFT) level of theory
• either generate the wfn/wfx file as part of the G16 job or using the *.fchk file
• BOTH cases you must use density=current or density=mp2 keyword

Using the *.fchk file

• you can see what density is available by running

grep -i '*.fck'

• for example

grep -i 'dens' HNO3_Dimer_c6_MP2_augccpVT+dZ_SP_wfx.fchk
# output=wfx density=mp2 mp2=full/gen int=ultrafine scf=conv
RMS Density                                R      6.409540209043613E-10
Total SCF Density                          R   N=       85905
Total MP2 Density                          R   N=       85905

• load the *.fchk file into Multiwfn
• then follow these steps

select 200 Other functions (Part 2)

16 Generate natural orbitals based on the density matrix in .fch/.fchk file

Input the type of density matrix, e.g. SCF, CI, CC, MP2, MP3, MP4...

e.g. If the .fch was produced by Gaussian at MP2 level and "density" keyword has been used, you may input "SCF" or "MP2"
Hint: You can manually open .fch file by text editor and search "density" to see which density matrices are available in this file

MP2

Done! Basis function information now correspond to natural orbitals

If next you intend to analyze real space functions based on the NOs, you should export new.mwfn in current folder and then reload it, so that GTF information will also correspond to NOs
Would you like to do this immediately? (y/n)

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• Then you can carry out the analysis you want. They density used now is the MP2 density