Note on the electron–electron counterbalance hole

The electron–electron counterbalance hole implies that two parallel spin electrons cannot be at opposite positions with respect to the spatial inversion center, if it exists. The hole is known to appear for any approximate and exact wave functions with an even inversion parity. We point out that for particular cases, the counterbalance hole also appears when wave functions have an odd inversion parity and two electrons with anti-parallel spins are involved.