The invention relates to a method and a
system for automatically calculating
Gibbs free energy of a material under different
temperature and pressure conditions and constructing a
phase diagram. The invention provides a method and a
system for automatically calculating
Gibbs free energy of a material and constructing a
phase diagram.
First principle calculation,
phonon free energy calculation and
hot electron free energy calculation are integrated into a unified automatic platform, so that the calculation efficiency is remarkably improved, and manual intervention is reduced. According to the
system, firstly, static self-consistent energy is obtained through calculation according to a
first principle,
phonon free energy is calculated in combination with a quasi-
harmonic approximation method, and
hot electron free energy is obtained through
electron state density analysis. On the basis, the compatibility among different calculation modules is ensured by adopting an automatic unit conversion and data preprocessing module. The system fits free energy-volume data through a three-order Birch-Murnaghan state equation, and supports adaptive
encryption sampling so as to accurately capture
phase change and free energy fluctuation under specific
temperature and pressure conditions. Finally, the system automatically draws a temperature-pressure
phase diagram, and an accurate basis is provided for predicting the thermodynamic stability of the material.