nwchem VS awesome-python-chemistry

I still use VMD sometimes but I don't use GAMESS anymore. It is a bit difficult to make recommendations without knowing your knowledge level and the operating system that you are using. If you are comfortable with Python, you could start with Psi4. If you know how to compile programs you can try building and running NWChem. Orca is also popular but I have not used it myself. If you are at a university you may have access to other proprietary quantum chemistry programs such as Gaussian or ADF. You can choose any of the programs available to you, and then follow the tutorials and examples in the manual. Once you understand the basics it is easy to learn how to use any program as they all share common features.

Yes, it works. See https://github.com/nwchemgit/nwchem/issues/320 and https://github.com/nwchemgit/nwchem/pull/326. I am an NWChem developer and M1 owner.

Okay, so I have no direct experience with the M1 and its specific feature set, but NWC does run with arm devices so it should not be problem (here is a link to compile on a mac MacOSNWChem . Also NWC is Open Sauce so just grab a copy and try it out.

Also I'd take a look through https://github.com/lmmentel/awesome-python-chemistry because I have a hard time believing this isn't a "solved problem" where you just need to find the right existing library.

This list of packages is probably a good place to start. It's a little unclear what your dataset looks like but at a guess you're going to need to parse molecular formulas and perhaps structures (you'll need to convert those into some machine-readable format like InChI). Sounds like you also need to consider molecular weight so you'll need a mass calculator if you don't have those values; you could build your own or leverage one of many available.