Multiwfn forum

MUDIT JAIN

Member

Registered: 2024-06-03

Posts: 23

Coordinates get reoriented in ETS-NOCV analysis

Respected Prof. Tian Lu,
First of all congratulations!! to you for your new publication in JCP. It contains a wealth of information and surely I will try to read it thoroughly.
Coming back to my query, Sir, recently I have been trying to perform ETS-NOCV analysis in Multiwfn but the coordinates get reoriented despite using "Nosymm" keyword during single point calculations. Does it has something to do with the formchk utility of Gaussian, which might have made some changes during the conversion of .chk file to .fchk ? Please help me in this issue. Thank you.

With regards
Mudit Jain

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,955

Website

Re: Coordinates get reoriented in ETS-NOCV analysis

Dear Mudit Jain

I think you didn't use nosymm properly. If nosymm has been used, there is no reason that Gaussian will automatically reorientate the system compared to geometry in the input file. Please double check. There is no any other thing to do.

Best,

Tian

MUDIT JAIN

Member

Registered: 2024-06-03

Posts: 23

Re: Coordinates get reoriented in ETS-NOCV analysis

Thank you so much for kind reply. I will try to run the calculation again.

With regards
Mudit

MUDIT JAIN

Member

Registered: 2024-06-03

Posts: 23

Re: Coordinates get reoriented in ETS-NOCV analysis

Dear Tian Lu,

After a sufficient number of trials, I can clearly state that: there must be some hidden problem that I am unable to decode. Because I have tried several examples and the same problem re-emerges. But when I tried ammonia-borane as an example, everything went perfectly. I even created input for the fragments using the .fchk file of the parent molecule but it still showed the same error. Also, I wish to mention that the example I tried was that of a carbodicarbene where I wished to visualize the NOCV orbitals between carbon(0) and the NHC fragments, but it did not go well, the same problem of different coordinates occurred. So, I think when we use the formchk utility, the coordinates get reoriented in some manner that the Multiwfn software is unable to process or match with the parent molecule.

At the end, with due respect, I request you Sir to kindly prepare a tutorial video/text/photo documentary of NOCV analysis of a molecule like carbodicarbene for which I shall be ever grateful to you.

With regards

Mudit

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,955

Website

Re: Coordinates get reoriented in ETS-NOCV analysis

Dear Mudit,

Formchk never changes coordinate. Note that when using Gaussian to perform calculation, if "nosymm" keyword is not specified, Gaussian will automatically put the system into standard orientation.

Best,

Tian

MUDIT JAIN

Member

Registered: 2024-06-03

Posts: 23

Re: Coordinates get reoriented in ETS-NOCV analysis

Dear Tian,

I once again thank you for your quick response. All I can do is keep trying and hope for the best. I shall come back to this post, the day I will succeed in finding the NOCV orbitals, till then I will try to correct any mistakes I am making.

With regards

Mudit