NaF: enthalpy of formation
2 accepted literature formation-enthalpy value(s) (experimental 1, DFT 1); experimental median -287.69 kJ/mol-atom (n = 1); Materials Project -283.373 kJ/mol-atom (mp-aaaaabag); OQMD -286.946 kJ/mol-atom (oqmd-5686).
Systems: F–Na
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -287.69 kJ/mol-atom | NaF | 298.15 | experimental | F–Na | [1] Zhang 2006 cites Chase 1998 | Table 2, p. 3, row 29 report | ||
| -269.597 kJ/mol-atom | NaF | 0 | DFT | first-principle calculations | F–Na | [1] Zhang 2006 | Table 2, p. 3, row 28 report |
Uncertainty budget
Components kept separate, in the value's unit (literature SCHEMA.md, UNCERTAINTY_CALIBRATION.md): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.
| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---|---|---|---|---|---|---|---|---|
| -287.69 | kJ/mol-atom | 5.000e-4 | 3.5 (unknown, calibrated) | 3.5 | ||||
| -269.597 | kJ/mol-atom | 5.000e-4 | 9.966 (dft, calibrated) | 9.966 |
DFT formation energies
Lowest-energy entries at this composition. Materials Project and OQMD use different energy references and are never averaged. 1 eV/atom = 96.485 kJ/mol-atom.
| Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical |
|---|---|---|---|---|---|---|---|
| Materials Project | mp-aaaaabag | -283.373 | -2.93696 | Fm-3m | 0 | 0 | no |
| OQMD | oqmd-5686 | -286.946 | -2.974 | Fm-3m | 0 | 0 | no |
DFT sources: A. Jain et al., Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002. doi:10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501-1509; S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010. doi:10.1007/s11837-013-0755-4 (CC BY 4.0);
Sources
- Shengjun Zhang, Carl Brubaker, Chao Jiang, Mei Yang, Yu Zhong, Qingyou Han et al., A combined first-principles calculation and thermodynamic modeling of the F–K–Na system, Materials Science and Engineering: A 418, 161-171 (2006). doi:10.1016/j.msea.2005.11.037