# Two body integral calculation taking too long

I'm running the most recent version of qiskit and am trying to run H2 in the cc-pvtz basis. However, it is taking an incredibly long time. This is what my code looks like:

molecule_coordinates = "H 0.0 0.0 0.0; H 0.0 0.0 0.735"
charge = 0
basis = 'cc-pvtz'
driver = PySCFDriver(atom=molecule_coordinates, charge=charge, unit=UnitsType.ANGSTROM, basis=basis)
molecule = driver.run()


It seems to be getting stuck in the two body electronic integral calculation. I'm not having any issues running with the sto-3g or cc-pvdz bases. I hadn't had this problem when running older versions of qiskit, so I'm wondering if this is just an issue with the update. If it is how can I get around it?

• Hello! I can reproduce this too, but I glanced through the Qiskit Nature code, and it looks like it passes the basis field on to PySCF and never directly examines it for itself. You might try opening an issue on their tracker; I glanced through and don't see one that's currently open. Oct 15 at 21:26