Defined by: \[A^{\sigma }=U^{\sigma }- T\ S^{\sigma }\] where \(U^{\sigma }\) is the @S06173@, \(T\) is the @T06321@, and \(S^{\sigma }\) is the @S06175@.
Source: PAC, 1972, 31, 577. (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 599 [Terms] [Paper]