Vibration frequencies

Hi dear,
I am optimizing a molecule, I prepared in Avogadro for optimization followed by Frequencies calculation. Unfortunately the output file when I open it in Avogadro or Jmol, give me the vibrations but the intensity column is empty.
I have tried in even small molecules like ethane but I keep getting the same problem.

Hi - it would help to know what version of MOPAC you used for the optimization and frequency calculations?

It would also help if you are able to share one of the files (e.g., post on Google Drive or Dropbox or even


Mopac version mopac-22.0.4-win (July 8, 2022 release)


I hope you can figure out the problem.

I would guess the format of the vibration data changed with this release (e.g., the move to GitHub).

I sent a request to get the file, I’ll let you know.

We won’t be able to fix Avogadro 1.x that you’re running, but we should be able to fix Avogadro 2 to support the new versions.

Thank you! I will look forward to your reply.

Normally how long take to get that fix in Avogadro 2?

I’m not sure, because I have a bunch of other things on my desk right now.