  The exact ground-state Kohn-Sham(KS) potential for the helium atom is known
from accurate wavefunction calculations of the ground-state density. The
threshold for photoabsorption from this potential matches the physical system
exactly. By carefully studying its absorption spectrum, we show the answer to
the title question is no. To address this problem in detail, we generate a
highly accurate simple fit of a two-electron spectrum near the threshold, and
apply the method to both the experimental spectrum and that of the exact
ground-state Kohn-Sham potential.
