I am trying to get electron repulsion integrals in the MO basis with MintsHelper.

I initiated the class instance with the basisset and tried to get mo_eri() but it throws up an error. I am nit sure what’s going wrong here?

Also, scf_wfn is the wavefunction object returned by psi4.energy(‘hf’, return_wfn=True).

My code snippet:

```
Ca = np.asarray(scf_wfn.Ca_subset('AO','ALL'))
basis = scf_wfn.basisset()
mints = psi4.core.MintsHelper(basis)
ao_eri = mints.ao_eri()
mo_eri_pis4 = mints.mo_eri(Ca,Ca,Ca,Ca)
```

The error:

```
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
/tmp/ipykernel_381763/1076174165.py in <module>
3 mints = psi4.core.MintsHelper(basis)
4 ao_eri = mints.ao_eri()
----> 5 mo_eri_pis4 = mints.mo_eri(Ca,Ca,Ca,Ca)
TypeError: mo_eri(): incompatible function arguments. The following argument types are supported:
1. (self: psi4.core.MintsHelper, C1: psi4.core.Matrix, C2: psi4.core.Matrix, C3: psi4.core.Matrix, C4: psi4.core.Matrix) -> psi4.core.Matrix
Invoked with: <psi4.core.MintsHelper object at 0x7fe8d98300f0>, array([[ 1.72637853e-04, 9.96107580e-01, 1.34603787e-03,
1.42351865e-01, 1.50625253e-01, 4.93247679e-02,
```