Hello PSI4-users,

I was following a tutorial to use psi4 api in python (https://github.com/psi4/psi4numpy/blob/master/Tutorials/01_Psi4NumPy-Basics/1g_basis-sets.ipynb). The example works fine, and I when I try to do similar thing with He-He(+) system I am hitting a roadblock. Here is my code:

```
import psi4
import numpy as np
psi4.core.set_output_file('output.dat', False)
hehe_plus = psi4.geometry("""
1 2
He 0.0 0.0 2.0
He 0.0 0.0 -2.0
""")
psi4.core.IO.set_default_namespace("hehe_plus")
def basisspec_psi4_yo__anonymous775(mol, role):
basstrings = {}
mol.set_basis_by_symbol("He", "HEonlyS", role=role)
basstrings['HEonlyS'] = """
cartesian
****
He 0
S 4 1.0
11.042785 -0.0577090
2.784478 -0.1869975
0.777509 -0.3561658
0.222223 -0.2708717
S 4 1.0
11.042785 -0.1051864
2.784478 -0.3909365
0.777509 -0.8380637
0.222223 1.4428743
****
"""
return basstrings
psi4.qcdb.libmintsbasisset.basishorde['USERDEFINED'] = basisspec_psi4_yo__anonymous775
psi4.set_options({'basis': 'userdefined',
'scf_type': 'pk',
'e_convergence': 11,
'd_convergence': 11})
eb, wfn = psi4.energy('scf', return_wfn=True)
mints = psi4.core.MintsHelper(wfn.basisset())
S = np.asarray(mints.ao_overlap())
T = np.asarray(mints.ao_kinetic())
V = np.asarray(mints.ao_potential())
H = T + V
print(S)
print(H)
```

The error I am getting is “QcdbException BasisSetNotFound”. I am not able to find where I was going wrong with the basis set definition. Any help is appreciated. Thank you very much.

Best Regards.