Thermodynamic properties of LiX(X=H, D, T) system investigated by density-functional theory

Some thermodynamic functions, mechanics and spectroscopic properties for LiX(X=H,D,T) were calculated with ab initio method. The vibration energy and vibration entropy for solid Li were calculated based on the quasi-harmonic Debye’s theory. The changes of thermodynamic functions were calculated and discussed, which are the enthalpy, reaction entropy, Gibbs free energy and equilibrium pressures of hydrogen gases for Li absorbing hydrogen isotopes processes. Results show that all the calculations are feasible. In the reaction of Li absorbing hydrogen gases, the enthalpy and reaction entropy are negative and their absolute values increase with the elevation of temperature, while Gibbs free energy increases toward the positive values. At the same temperature and pressure, the substitutions of