Activity Coefficients and Other Thermodynamic Characteristics of $\mathrm{Li}$–$\mathrm{LiH}$ ($\mathrm{LiD}$, $\mathrm{LiT}$) Binary Solutions at Liquid–Vapor Phase Equilibrium

A $\mathrm{Li}$–$\mathrm{LiH}$–type system at liquid–vapor phase equilibrium is considered. The experimental data on vapor pressure is processed, and the approximate equations for the temperature dependence of the equilibrium constant, activity coefficients, and other thermodynamic characteristics are found. The presence of an analog of the Sieverts constant in the region of liquid hydride concentrations in solution at $x \approx 1$ is found for the first time. Previously unknown dependences for the $\mathrm{Li}$–$\mathrm{LiT}$ system are obtained.