The FCIDUMP format is probably the closest thing to what you are seeking. More than a dozen different quantum chemistry programs already have a built-in mechanism to read or write one- and two-electron integrals in FCIDUMP format, as described here: How do the various programs read or write integrals in FCIDUMP format?
"which doesn't compromise on ...
You can use OpenBabel directly to obtain the Gaussian input from command line.
OpenBabel supports two types of Gaussian input generation:
Gaussian 98/03 Cartesian Input
Gaussian Z-matrix Input
To run OpenBabel:
obabel [-i<input-type>] <infilename> [-o<output-type>] -O<outfilename> [Options]
Take a look at this answer for ...
You don't mention your molecule, which would help a lot. I'm trying to figure out how one gets 7 vibrational modes including translations and rotations... 3N will never equal 7, and 3N-5 = 7 would imply 3N = 12, so 4 atoms? If there was only one vibration, then it's a diatomic, but we'd only see 6 modes from 2 atoms.
If you can mention what the molecule is, ...
Your question is quite clear and on point, however it is a bit difficult to reply with the information you provided.
I have never used GAMESS myself, so I cannot help you with the specific commands.
I do not know on which molecules you are working, but it would be useful to know in order to reply.
If the output is the eigenvalues of the Hessian matrix then ...
The only thread I could find that had some discussion of this on the NBO forum was related to using the NBO interface in Gaussian and was likely about an earlier version of NBO based on the discussion being from 2016.
However, the answerer there seems to be an NBO developer and he mentions that these linear dependency failures can often be resolved by ...