Fitting Lennard-Jones Parameters from Potential Energy Scan

Hello psi4 users and developers,

I am trying to scan a potential energy surface for Ar + CH4 to calculate the subject parameters following the example given here

and the one under the psithon tutorial in the documentation but I can’t get my geometries to work. I tried several geometries but each time I get an exception
Unprocessable Molecule remanents under [psi4, xyz, xyz+, psi4+]:
How can I create such a geometry.


Hi, maybe post one of your inputs?

CH4_AR.dat (1.1 KB)

Sorry for the mess! Attached find a text file for the input

Please use the formatting options (preformatted text) in the editor, upload as file, or format with backticks manually.

I dont think you can assign r6=R in the Z-matrix. Instead, use r6 directly in the above or rename r6 to R.
You need equal signs in the Z-matrix parameters like this: r2= 1.10940.
You need to define fragments by writing -- above the Argon line if you want to use the automatic BSSE procedure.

That’s as much as I can see right now

You need to use an equals sign between the symbol and the geometry parameter when assigning in your Z-matrix. See input 6 of the tutorial you linked for an example.

Thanks. I think I generated this geometry for gaussian and I forgot the “=” sign when editing to run on psi4. Thank you very much