Extension of Landau-Ginzburg free-energy functionals to high-gradient domains

The Landau-Ginzburg (LG) free-energy-gradient theory is extended to account for domains of intermediate wavelengths. The extension is nonlocal but preserves the universal features of the LG theory, has the same level of complexity, and reduces to it in the small-gradient limit. It also enables one to gain a meaningful insight into the microstructure of a system.