Reliability evaluation of thermophysical properties from first-principles calculations

Area of Science:

• Materials Science
• Computational Physics
• Thermodynamics

Background:

• Thermophysical properties (heat capacity, bulk modulus, thermal expansion) are crucial for technological applications.
• Traditionally, these properties are determined experimentally, which can be time-consuming and costly.
• Advancements in computational methods offer an alternative for obtaining temperature-dependent data.

Purpose of the Study:

• To evaluate the accuracy and reliability of various first-principles computational methods for predicting temperature-dependent thermophysical properties.
• To compare the impact of different computational codes, pseudopotentials, and phonon determination methods on the accuracy of these properties.
• To assess the consequences for the use of first-principles data in computational thermodynamics.

Main Methods:

• Utilized first-principles calculations using QUANTUM ESPRESSO and VASP codes.
• Employed ultrasoft and projector augmented wave pseudopotentials.
• Applied linear response and direct force constant methods for phonon calculations.

Main Results:

• Analysis of thermophysical properties for Chromium (Cr) and Nickel (Ni) was performed.
• Comparison of computed data against experimental scatter was conducted.
• The study identified the influence of different computational parameters on property prediction.

Conclusions:

• First-principles computational methods can provide reliable temperature-dependent thermophysical data.
• The choice of computational codes, pseudopotentials, and phonon methods significantly impacts the accuracy of predicted properties.
• Understanding these influences is critical for the reliable application of computational thermodynamics.