'psi4.core' has no attribute 'opt_clean'

[Rdk0]

on Ubuntu 20.04 the following

pk = Psikit()
methanol = 'CO'
pk.read_from_smiles(methanol)
pk.optimize()

generates this output:

Optimizer: Optimization complete!
followed by this error message:

AttributeError Traceback (most recent call last)
Cell In[11], line 4
2 methanol = 'CO'
3 pk.read_from_smiles(methanol)
----> 4 pk.optimize()

File ~/miniconda3/envs/psi4/lib/python3.8/site-packages/psikit/psikit.py:82, in Psikit.optimize(self, basis_sets, return_wfn, name, multiplicity, maxiter)
79 self.mol = self.xyz2mol()
81 if not self.debug:
---> 82 self.psi4.core.opt_clean() # Seg fault will occured when the function is called before optimize.
83 return scf_energy

AttributeError: module 'psi4.core' has no attribute 'opt_clean'