  We present evidence that operation of QCA (Quantum Cellular Automaton) cells
with four dots is possible with an occupancy of 4N+2 electrons per cell (N
being an integer). We show that interaction between cells can be described in
terms of a revised formula for cell polarization, which is based only on the
difference between diagonal occupancies. We validate our conjectures with full
quantum simulations of QCA cells for a number of electrons varying from 2 to 6,
using the Configuration-Interaction method.
