higher-order transition

Synonym: smooth transition
https://doi.org/10.1351/goldbook.H02822
A general term used to describe a transition in which the first and second derivatives of the molar @G02629@ or molar @H02772@ (or @C01032@) with respect to temperature and pressure are continuous, but derivatives of some higher order are discontinuous at the transition point. Synonymous with smooth transition.
Source:
PAC, 1994, 66, 577. (Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)) on page 583 [Terms] [Paper]