In recent years, many advanced thin films had been successfully prepared under activated nonequilibrium conditions. However, based on classical thermodynamics the low-pressure diamond synthesis had been regarded as violating the second law of thermodynamics. After removing the “bug” hidden in classical concepts of thermodynamics, a new field of modern thermodynamics, nonequilibrium nondissipative thermodynamics, emerges in the equality part of the second law. The new progress in the second law of thermodynamics provides a firm theoretical base of calculating nonequilibrium phase diagrams for advanced thin films. Thermodynamic coupling in these systems has been discussed from both sides in physics and in mathematics. Our coupling model for diamond films growth was cited in the Journal <i>Nature</i> with a nice comment.