I’m running a test RHF/STO-3G calculation on a H24C48S2 molecule, against a Conda-based Psi4 installation. (I’m using the openfermionpsi4 interface, but the question is kind of in between Psi4 and the interface) The calculation is proceeding fine, but I notice I’m only getting a single thread in spite of asking for 4.
Would this approach lead to observable CPU utilization around 400% via, e.g., htop? I’ve looked at the run_psi4 interface and it doesn’t have a thread count argument, but I’m hoping I can avoid customizing it to pass a thread count argument if there’s a trick. Thanks in advance.
I can’t give a definitive answer without looking into the guts of OpenFermion, but I’d expect that supplying set_num_threads should parallelize.
Are you trying that and not seeing parallelization, or are you asking before you’ve even tried? If you need additional support on this, please state your OS.
I should also state as a disclaimer: I don’t understand why you would study a system with this many orbitals if your interests are in quantum computing, and I don’t understand why you would use OpenFermion if your interests aren’t in quantum computing. If you are sure you know what you’re doing, carry on.
Hi Jonathon, thanks. I did actually try it, but before getting too much deeper wanted to make sure there wasn’t a well-known trick. I’ve wanted to use Psi4 for awhile, but this is the first time I had good reason to start.
Re: quantum computing, it will be an active space calculation. We’re just exploring bounds of NISQ for now, and the phenomenon we’re interested in is primarily contained in a smallish active space around the frontier orbitals. Still working out whether and how the QC frameworks represent the aufbau core of systems; if they don’t, then we have our next proposal. If they do, then we’ll see how far we can push the active space.