SQS - Special quasirandom structures
“Chemical disorder can also be modeled, if the DFT calculations are performed with sufficiently large supercells. The degree of artificial order in a (small, periodically repeated) supercell is quantified by correlation functions attributed to a selected set of structural motives. The atomic configurations for which these values are closest to an infinite random alloy are called special quasirandom structures (SQS).” (Jorg, 2013)
SQS |
POSCAR File |
Author |
Year |
Reference |
|
| FCC | 16atomfcc.2575 | C Wolverton | 2001 | DOI | |
| 16atomfcc.5050 | |||||
| BCC | 16atombcc.2575 | Chao Jiang | 2004 | DOI | |
| 16atombcc.5050 | |||||
| HCP | 16atomhcp.2575 | Dongwon Shin | 2006 | DOI | |
| 16atomhcp.5050 | |||||
| L12 | (A,B)B3SQS.2575 | Tao Wang | 2006 | DOI | |
| (A,B)B3SQS.5050 | |||||
| A(A,B)B2SQS.2575 | |||||
| A(A,B)B2SQS.5050 | |||||
| Ternary FCC | 16atomSQS.502525 | Dongwon Shin | 2007 | DOI | |
| 24atomSQS.333333 | |||||
| 32atomSQS.502525 | |||||
| B2 | A1(B0.5,C0.5) | Chao Jiang | 2005 | DOI | |
| A1(B0.75,C0.25) | DOI | ||||
| Ternary BCC | 36atombcc.A1B1C1 | Chao Jiang | DOI | ||
| 32atombcc.A2B1C1 | |||||
| 64atombcc.A2B3C3 | |||||
| 64atombcc.A6B1C1 | |||||
| Perovskite: ABO3 | ABO3-Perovskite | James Saal | N/A | ||
| Garnet: A3B5O12 | A3B5O12-Garnet | James Saal | N/A | ||
| DHCP | DHCPSQS.5050 | Swetha Ganeshan | N/A | ||
| MgB2 | MgB2SQS | Arkapol Saengdeejing | N/A | ||
YPHON
We propose a mixed-space approach using the accurate force constants calculated by the direct approach in real space and the dipole–dipole interactions calculated by linear response theory in reciprocal space, making the accurate prediction of phonon frequencies for polar materials possible using the direct approach as well as linear response theory. As examples, by using the present approach, we predict the first-principles phonon properties of the polar materials α-Al2O3, MgO, c-SiC, and h-BN, which are in excellent agreement with available experimental data.