Installing Optional Plugins for Psi4

[Chikakoyanagida]

Hi,

I have been using psi4 on its own for a while and now I am looking to extend its utility by adding more optional plugins as displayed in the https://psicode.org/installs/v182/# such as ambit, chemps2, etc. I am a bit confused about how these are implemented. Do I have to manually reinstall psi4 from source? I am asking since I could not find a straightforward way add those to my existing psi4.

Many thanks in advance!

[loriab]

It depends on which ones you're targeting and how you're getting psi4. If you're building from src, you'd -D ENABLE_<addon>=ON as described here https://github.com/psi4/psi4/blob/master/CMakeLists.txt#L69-L108 . (Note that "addon"s is what you'd want to search; "plugins" are different in psi4.)

If you're using the conda binary, it varies by the nature of the addon. Addons that have to be enabled/disabled at psi4-build-time tend to be already in the psi4 binary. Unfortunately CheMPS2 is one that hasn't been transitioned to conda-forge yet due to license issues. You could grab psi4 v1.7 to use it. Ambit is available to install from c-f. Other addons that psi4 doesn't need to know about at compile time, like cppe or dftd3, can be conda installed at any time.

That's the general picture. I can probably help on specifics if you run into difficulties.

[Chikakoyanagida]

Thank you loriab! I am mainly looking to install ambit so that I can compile forte. On the way I found CheMSP2 to be potentially useful. Is there a way I could independently install CheMSP2 in the same conda environment as Psi4?

[loriab]

Ambit's easy, conda install pyambit -c conda-forge. There's nothing in psi that actually links to it, so it's fine to simply install psi4 binary and ambit binary into the same env.

For CheMPS2, are you wanting to run chemps2 through psi4? That's easy to enable if you're building psi4 from src. But there isn't a good sol'n for using psi4 binary. I'd suggest compiling chemps2 from src if you want chemps2 w/o psi4 linkage. Or wait until we finally re-plugin-ize it.

[JonathonMisiewicz]

Obligatory ping to @fevangelista on things Forte.