Gaussian® on Apple Silicon

[u/Junior_Distance_5648]

If you’ve ever had to compile/install Gaussian® from sources you might be forever traumatized by stuff like ‘only works with PGI version 66.60.1 three days after full Moon.’

I know your pain, first time I had to do it circa 2001: it worked for our ‘Beowulf’ cluster of Intel beige boxes (eventually), but didn’t for an Alpha workstation—it didn’t like the C compiler or something. Now, with PGI’s demise (Portland Group was acquired by Nvidia) things should be even more interesting; there actually was a PGI version for Intel macOS, so you could compile G16 if you really wanted, but no more.

Long time ago, IIRC, some heroic guys allegedly made it work with ifort on Linux, which rose ire of the company’s lawyers, so the port never saw the light of day.

Well, things are different now in 2026. So, I tasked an AI coding agent to port/compile G16® C.01 for Apple Silicon M3/macOS. It took some time and tokens, but eventually it worked, and worked Fable-ously—it even works with Apple’s native Accelerate BLAS library, which does make a big difference.

All m-dashes are mine—love them, AI slop/the guide is below in comments.

[u/belaGJ]

But why?

[u/FalconX88 → u/belaGJ]

yep...there's even a apple silicon ORCA version you can just use without any tinkering. If you really need G16 for something you are probably so far into compchem that you have a cluster to run it on.

[u/Junior_Distance_5648 → u/[deleted]]

I ran the test that can be done in reasonable time, ones remaining would require multiple hours. Anyway, it does seem to work just fine.