Solid-State Functional Materials Without Phase Transitions: A Structural Admissibility Condition for Phase-Invariant Functional Persistence

Description This document establishes phase-invariant solid-state functionality as a structural admissibility condition for materials claiming operational persistence in capture, storage, thermal, or structural applications. The analysis is strictly non-constructive and defines invariant boundary conditions under which functional performance must arise from stable solid-state identity rather than melt, freeze, boil, latent-heat cycling, or operational phase switching. The framework constrains patentability at the level of enablement, inventive step, and industrial applicability. It defines necessity conditions only and does not claim sufficiency.