This makes it kinetically nonreactive despite being thermodynamically one of the strongest oxidants. These varying thermodynamically stable contact angles are known as metastable states. Black phosphorus is the least reactive allotrope and the thermodynamically stable form below . Spinodal decomposition occurs for phases that are thermodynamically unstable. It is possible that a physical process is logically reversible but thermodynamically irreversible. Alumina is more thermodynamically stable in oxygen than chromia. It is also possible that a physical process is logically irreversible but thermodynamically reversible. All of these analogues are thermodynamically unstable. Most useful structures require complex and thermodynamically unlikely arrangements of atoms. Erasing information is a thermodynamically irreversible process that increases the entropy of a system. All real-world oscillator systems are thermodynamically irreversible. It is thermodynamically stable and fairly soft metal. Thus, imidazole-2-ylidenes are thermodynamically stable. The materials are thermodynamically stable at high pressures. Absorption spectroscopy allows the study of samples that are thermodynamically stable at room temperature.