Applicability of special quasi-random structure models in thermodynamic calculations using semi-empirical Debye–Grüneisen theory

Influence of Mg Doping on the Structure and Mechanical Properties of Al2Cu Precipitated Phase by First-Principles Calculations

“…The simulation temperature was set as 0 to 2000 K, and the system pressure was set as 0 to 20 GPa for the first-principles calculations. Although there are some errors in the results of the quasi-harmonic Debye model used in the thermodynamic calculations, they are in the same order of magnitude as the experimental values [ 43 ], so the fluctuations and trends of the thermodynamic properties of the precipitated phase can be predicted approximately. The E-V curve of the Al 2 CuMg 6 precipitated phase was plotted in Figure 6 .…”

“…The simulation temperature was set as 0 to 2000 K, and the system pressure was set as 0 to 20 GPa for the first-principles calculations. Although there are some errors in the results of the quasi-harmonic Debye model used in the thermodynamic calculations, they are in the same order of magnitude as the experimental values [43], so the fluctuations In an isotropic system, the 3D closed surface representing the relation between the elastic modulus and the crystallographic direction should be spherical. The degree of deviation from the sphere reflects the degree of anisotropy.…”

Surface energies in high‐entropy carbides with variable carbon stoichiometry

“…29,30 In order to generate chemical disorders, the special quasi-random structure (SQS) approach was adopted using the mcsqs code of Alloy Theoretic Automated Toolkit. 31,32 SQS bulk supercells of a size of 2 × 2 × 2 with 64 atoms were first generated based on the rock salt structure type of Fm 3m space group, as shown in Figure 1A, and then the periodic slab models with 8 layers, 9 layers, and 11 layers were utilized to simulate (1 0 0), C-(1 1 1), and metal-(1 1 1) surfaces, respectively. The constituent metal elements of HECs in the slab models satisfied the equipartition ratio, and the height of vacuum region was set as 15 Å for each slab model.…”

“…On the basis of density‐functional theory, the first‐principles calculations were performed by Vienna Ab initio Simulation Package with the project‐augmented wave method and the Perdew–Burke–Ernzerhof version of exchange–correlation functional 29,30 . In order to generate chemical disorders, the special quasi‐random structure (SQS) approach was adopted using the mcsqs code of Alloy Theoretic Automated Toolkit 31,32 . SQS bulk supercells of a size of 2 × 2 × 2 with 64 atoms were first generated based on the rock salt structure type of Fm $${\rm{\bar 3}}$$ m space group, as shown in Figure 1A, and then the periodic slab models with 8 layers, 9 layers, and 11 layers were utilized to simulate (1 0 0), C‐(1 1 1), and metal‐(1 1 1) surfaces, respectively.…”

The Role of Auxiliary Alkali Metal Ions on Scheelite Structure Double Molybdate and Tungstate Phosphors

“…This type of disordered scheelite structure has hindered theoretical calculations because of the difficulty in constructing the disordered model. There are several methods − to overcome this obstacle, and herein, the supercell method was adopted to express disordered models . Throughout the investigation, the role of alkali-metal ions was investigated to better understand the origin of the superior luminescent properties of double tungstate and molybdate phosphors.…”