We believe there is an issue in Psi4 which causes the RDMs of odd-numbered electron systems to be unphysical. Somehow, these RDMs have the correct energy the individual elements are sometimes greater than 1 or less than -1, which is impossible. We should first make absolute sure that this is due to Psi4, not an error on our end. Then point it out to the Psi4 developers. Next, we should add a warning to our code that is raised when one asks for the RDM of an odd-numbered electron system. Hopefully this is not an issue in pyscf.
We believe there is an issue in Psi4 which causes the RDMs of odd-numbered electron systems to be unphysical. Somehow, these RDMs have the correct energy the individual elements are sometimes greater than 1 or less than -1, which is impossible. We should first make absolute sure that this is due to Psi4, not an error on our end. Then point it out to the Psi4 developers. Next, we should add a warning to our code that is raised when one asks for the RDM of an odd-numbered electron system. Hopefully this is not an issue in pyscf.
This error is demonstrated in "known_errors.py".