Same total energy with AIMAll with regular and self-consistent NL corr

prasanta13 · 2025-01-09 16:12:58

Hello Prof Tian,
I have run a regular PBE and PBE SCNL calculation with ORCA and obtained the .wfx files from orca_2aim. Now, with the wfx files, I have run AIMAll and found that the AIMAll obtained energies are similar whereas energies obtained from ORCA are very different.
Here is the ORCA input with SCNL

! PBE SCNL VERYTIGHTSCF NORI AIM KEEPDENS
%maxcore 8000
%pal
nprocs 8
end
%method
IntAcc 7
end
%basis
Basis "aug-cc-pVTZ"
end

* xyzfile 0 1 mp2_opt_AVTZ.xyz

With energy = -381.7650100511 Hartree

And ran PBE calculation with the same input as above without "SCNL".
With energy = -381.952393605 Hartree

Now, with the obtained .wfx Files, I had to add
<Model>
PBE
</Model>

Which I did to both SCNL and non-SCNL .wfx files and ran AIMAll.
AIMAll gives total energy as,
PBE-SCNL = -381.952350
PBE = -381.952365
And both are relatively same.

So, does the SCNL keyword change the density? or it is the problem with AIMAll? Such that providing any .wfx files (even produced by M06) with <Model> as PBE will also give the same energy?

Thank you very much
Prasanta

sobereva · 2025-01-09 17:19:56

VV10 is a dispersion correction method, which affects electronic energy notably, but has little influence on wavefunction. The energy derived from AIM analysis given in this case doesn't consider dispersion correction to energy.

prasanta13 · 2025-01-10 10:36:50

I agree on that part that it is a dispersion correction method. However, from the ORCA 6.0.1 manual, I find this,
"The use of the keywords !B3LYP SCNL would request a self-consistent treatment in
which orbitals and density are optimized in the presence of the full B3LYP + VV10 exchange-correlation potential."

Doesn't that mean that the .wfn file is also changed notably?

sobereva · 2025-01-10 16:48:21

SCNL only marginally affects the resulting wavefunction. You can plot a electron density difference map using Multiwfn between the wavefunction obtained with and without SCNL, you will find the difference is almost negligible.

prasanta13 · 2025-01-12 12:27:39

Yes, this is true. I have checked the same as you suggested. At the intermolecular region, only a small amount of density increase is found. On the other hand, around the atoms, small amount of density is decreased. The threshold I set for the plot is 5e-5 unit.

Multiwfn forum

#1 2025-01-09 16:12:58

Same total energy with AIMAll with regular and self-consistent NL corr

#2 2025-01-09 17:19:56

Re: Same total energy with AIMAll with regular and self-consistent NL corr

#3 2025-01-10 10:36:50

Re: Same total energy with AIMAll with regular and self-consistent NL corr

#4 2025-01-10 16:48:21

Re: Same total energy with AIMAll with regular and self-consistent NL corr

#5 2025-01-12 12:27:39

Re: Same total energy with AIMAll with regular and self-consistent NL corr

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