Simulation of the morphological instability, known as the Asaro-Tiller-Grinfeld instability, of a strained film. Anisotropy depicts a SiGe system. For more explanation, see Aqua and Frisch, Phys. Rev. B (2010) http://prb.aps.org/abstract/PRB/v82/i8/e085322 and Aqua web page http://www.insp.upmc.fr/jnaqua.html