Computation of thermodynamic properties of quarternary and higher order systems from binary data using shortest distance composition paths

Abstract

Equations for the computation of integral and partial thermodynamic properties of mixing in quarternary systems are derived using data on constituent binary systems and shortest distance composition paths to the binaries. The composition path from a quarternary composition to the i-j binary is characterized by a constant value of (X_i - X_j). The merits of this composition path over others with constant values for X_i/X_j or X_i are discussed. Finally the equations are generalized for higher order systems. They are exact for regular solutions, but may be used in a semiempirical mode for non-regular solutions.