  Random sequential adsorption with diffusional relaxation, of two by two
square objects on the two-dimensional square lattice is studied by Monte Carlo
computer simulation. Asymptotically for large lattice sizes, diffusional
relaxation allows the deposition process to reach full coverage. The coverage
approaches the full occupation value, 1, as a power-law with convergence
exponent near 1/2. For a periodic lattice of finite (even) size $L$, the final
state is a frozen random rectangular grid of domain walls connecting
single-site defects. The domain sizes saturate at L**0.8. Prior to saturation,
i.e., asymptotically for infinite lattice, the domain growth is power-law with
growth exponent near, or possibly somewhat smaller than, 1/2.
