CISD calculation

I tried to run the following commands for 3 molecules: H3+, CH5+, and C7H5O4.

myhf = scf.RHF(mol).run()
myci = ci.CISD(myhf).run()
wf_cisd = import_state(myci, tol=1e-1)

It works for H3+ and CH5+ but fails to the last one

IndexError                                Traceback (most recent call last)
Cell In [8], line 1
----> 1 wf_cisd = import_state(myci, tol=1e-1)

File ~/.local/lib/python3.9/site-packages/pennylane/qchem/, in import_state(solver, tol)
    628     wf = _wfdict_to_statevector(wf_dict, len(solver[0][0]))
    629 else:
--> 630     wf = _wfdict_to_statevector(wf_dict, solver.mol.nao)
    632 return wf

File ~/.local/lib/python3.9/site-packages/pennylane/qchem/, in _wfdict_to_statevector(wf_dict, norbs)
    655     bin_b += "0" * (norbs - len(bin_b))
    656     bin_ab = "".join(i + j for i, j in zip(bin_a, bin_b))
--> 657     statevector[int(bin_ab, 2)] += coeff
    659 statevector = statevector / np.sqrt(np.sum(statevector**2))
    661 return statevector

IndexError: only integers, slices (`:`), ellipsis (`...`), numpy.newaxis (`None`) and integer or boolean arrays are valid indices

Can someone help me?
Attached is the file created to run (2.2 KB)

Hi @souzateixeira, that last molecule is very very big. Unless you’re running this on a very large cluster you’re going to run out of memory. Unfortunately I don’t think any of the usual tricks will be enough to run that molecule. I’m sorry I don’t have better news for you.