We propose an unconditionally stable semi-implicit time discretization of the phase fieldcrystal evolution. It is based on splitting the underlying energy into convex and concaveparts and then performing H-1 gradient descent steps implicitly for the formerand explicitly for the latter. The splitting is effected in such a way that the resultingequations are linear in each time step and allow an extremely simple implementation andefficient solution. We provide the associated stability and error analysis as well asnumerical experiments to validate the method’s efficiency.
