Multiwfn forum / energy decomposition analysis using combined fragment wavefunctions

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (sobereva) — Mon, 11 Jan 2021 11:42:51 +0000

It is really difficult to give an explanation of your observation without additional information. It is best to send me your optimized structures via E-mail, also providing your Gaussian input files will be useful.

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Sun, 10 Jan 2021 21:29:21 +0000

Dear Tian
Thank you for your quick response. We are sure about the basis sets and the calculations. We have used the 6-311++G(d,p) for C, H, N, O and Cl- as well as Def2-TZVP for metal atoms. These basis sets have used for these interactions in literature. You have already said me that this term can be positive and negative in the EDA analysis. In fact, I want to know when the Eelectrostatic+exchange term can be positive or negative. If there if a reason for that, please let me know.
Best Regards,
mehdi

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (sobereva) — Sun, 10 Jan 2021 19:29:27 +0000

Dear Mehdi,

It is really difficult to give you a definitive answer without more information, there are many possible reasons. For example, incorrect setting of basis set and pseudopotential in input file, the SCF was not converged to stable wavefunction, incorrect calculation step, etc.

Best regards,

Tian

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Sun, 10 Jan 2021 18:09:53 +0000

Dear Tian,
We have investigated the interaction of Mn (M = Cu, Ag, and Au; n =1-4) nanoparticles with ChCl:Urea molecule. We have done the EDA using Multiwfn program. In the energy decomposition analysis of the complex (attached file), why the electrostatic+exchange repulsion terms are completely positive for the Au nanoparticles, while it is mostly negative for the Cu and Ag systems. What is structurally different among these systems that contribute to this trend.
Thank you in advance for the time you devote to answer my question.

Picture1.zip

Best regards,
Mehdi Shakourian-Fard

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Tue, 05 Jan 2021 18:49:52 +0000

Dear Tian
Thank you so much for your help.

Best regards,
Mehdi Shakourian-Fard

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (sobereva) — Tue, 05 Jan 2021 18:23:28 +0000

Dear Mehdi shakourian-Fard,

Please simply ignore the red color, it never means that the interaction is repulsive, it just comes from the drawback of the definition of sign(lambda2)rho function. In the circular red color region, the sign of lambda2 happens to change to positive, this observation doesn't have any noteworthy chemical significance.

If you slightly adjust isovalue of RDG to make the isosurface slightly shrink, the red edge may disappear.

By the way, the grid spacing of your RDG analysis is too large, therefore the isosurfaces look unsmooth. I suggest properly decreasing the grid spacing to make the graph finer.

Best regards,

Tian

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Tue, 05 Jan 2021 17:24:02 +0000

Dear Admin,
I have plotted a RDG surface for my structure. We are considering the interaction of Choline chloride (ChCl):Urea complex with Ag, Au and Cu clusters. I know that the interaction between the Cl- anion in the ChCl:Urea complex with nanoclusters is attractive in nature (blue color or electrostatic interaction, whereas we can see some red colors (repulsive force). I appreciate if you give us a reasonable explanation for seeing the red observation?
Picture2.zip

Bset regards,
Mehdi shakourian-Fard

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Thu, 02 Apr 2020 08:07:06 +0000

Dear Admin
Thank you so much for all your help.

Best regards,
Mehdi Shakourian-Fard

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (sobereva) — Wed, 01 Apr 2020 22:46:21 +0000

The -14.74 corresponds to the sum of ΔE_electrostatic and ΔE_exchange (see Section 3.100.8 of Multiwfn manual), in principle it can be positive or negative, only in some papers the authors labelled it as ΔE_steric for discussion convenience; note that the word "steric" in this context is not consistent with the steric effect in common sense (in fact the steric effect is represented by the ΔE_exchange). So, I suggest you report -14.74 in your work as ΔE_electrostatic + ΔE_exchange instead of ΔE_steric, which is somewhat misleading.

The ΔE_dis must be negative. You can obtain it in terms of DFT-D dispersion correction, as mentioned in Section 3.100.8 of Multiwfn manual.

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Wed, 01 Apr 2020 09:58:18 +0000

Dear Admin,
I calculated the ΔEtot, ΔEorb and ΔEsteric as follows:
ΔEtot= -387.98
ΔEorb= -373.24
ΔEsteric = -14.74
I think ΔEsteric should be positive, while i have calculated it with negative value. Am i right? How is the sign of ΔEdis in energy decomposition analysis?
Best regards,
Mehdi Shakourian

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Wed, 01 Apr 2020 08:02:25 +0000

Dear Admin
The problem was solved with "genecp" keyword. I really appreciate for your help.

Best regards,
Mehdi Shakourian

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (sobereva) — Tue, 31 Mar 2020 17:33:20 +0000

In the new.gjf, you should use genecp instead of gen, otherwise the pseudopotential information will not be loaded.

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Tue, 31 Mar 2020 10:29:24 +0000

Dear Admin
Thank you so much for your help. I used the modifications in the input files but I couldn't solve the problem. I appreciate if you see the input files (attached files) and check it again.

Best regards
Mehdi Shakourian-Fard

inputs.part04.rar
inputs.part03.rar
inputs.part02.rar
inputs.part01.rar
inputs.part05.rar
inputs.part06.rar

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (sobereva) — Sun, 22 Mar 2020 14:21:26 +0000

You should replace 5(E16.9) in the gjf file by (5E16.9).

I think the Multiwfn you are using is not the latest version on Multiwfn website, because this problem has been identified about one month ago and fixed.

In addition, when you calculating the Hg, plate and then the complex, please always add "5d" keyword. (Gaussian uses 6d type of basis function when 6-31G* is employed, while uses 5d type of basis function when "gen" keyword is employed, this causes evident inconsistency, while using "5d" keyword can fully eliminiate this problem).

If after doing above modifications, the calculation of complex is still unsuccessful, please upload the gjf file for Hg and that for plate, I will check.

Re: energy decomposition analysis using combined fragment wavefunctions

dummy@example.com (Mehdi) — Sun, 22 Mar 2020 09:11:36 +0000

Dear Admin,
Thank you so much for your quick reply. I used the last version of Multiwfn 3.7. Unfortunately, I see the error again. The input file was too large. Thus, the file was divided into seven sections. Please use the seven links below, download the files, put them in a folder and extract. I appreciate if you see the error.
Best regards,
Mehdi Shakourian
File.part01.rar
File.part02.rar
File.part03.rar
File.part04.rar
File.part05.rar
File.part06.rar
File.part07.rar