Multiwfn forum

sonalis

Member

Registered: 2023-02-25

Posts: 13

NTO calculation files

Hello! Greetings!

I want to do NTO calculations for which two files are needed i.e., .fch and .out files. I had queries regarding
1. How to generate .fch file from gaussian? What keyword do we need to add to get the .fch file (like we add 'formcheck' to get .fchk file format)?
2. Can we use .log file instead of .out file? If not, then how to get .out file?

Thank you

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,777

Website

Re: NTO calculation files

1 Usually, use%chk=xxx.chkin .gjf to request Gaussian to save .chk file after calculation, then manually useformchk xxx.chkto get xxx.fchk in current folder.

2 .log is exactly the same as .out, different people prefer to use different suffix. For Multiwfn, both .out and .log are valid suffix of Gaussian output file.

sonalis

Member

Registered: 2023-02-25

Posts: 13

Re: NTO calculation files

So, .fchk file will also work just like .fch file. Thank you so much Sir for your kind response.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,777

Website

Re: NTO calculation files

Essentially .fchk is exactly the same as .fch, only differs by suffix.

sonalis

Member

Registered: 2023-02-25

Posts: 13

Re: NTO calculation files

For some singlet or triplet states (during nto calculations), the homo lumo gap for nto's are showing 0 eV, which is not possible. Also, some nto's which should have been n-pi* transitions, are not showing so. Please help me to figure out where I'm going wrong.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,777

Website

Re: NTO calculation files

After performing NTO analysis, there is no HOMO and LUMO concept.