In the epitaxial thin film literature, it is sometimes claimed that epitaxial strains can be used to stabilize phases of a material that are not the normally stable (equilibrium) phase. Estimate the magnitude of strain energy for a GaAs* film that is under an elastic strain, , of 0.2%. Compare the strain energy in units of eV/per atom and with the chemical energy (formation energy) of GaAs in the same units and comment on the feasibility of such approaches.