Ga4Na: enthalpy of formation
3 accepted literature formation-enthalpy value(s) (experimental 2, model 1); experimental median -19.2 kJ/mol-atom (n = 2); Materials Project -13.759 kJ/mol-atom (mp-aaaaaarm); OQMD -15.938 kJ/mol-atom (oqmd-17259).
Systems: Ga–Na
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -20.9 kJ/mol-atom | Ga4Na | 723.15 | experimental | Ga–Na | [1] Wang 2007 cites Zabdyr 1983 | Table 3, p. 4, row 3 report | ||
| -17.5 kJ/mol-atom | Ga4Na | 723.15 | experimental | Ga–Na | [1] Wang 2007 cites Gambino 1973 doi | Table 3, p. 4, row 2 report | ||
| -20.1 kJ/mol-atom | Ga4Na | 723.15 | model | Ga–Na | [1] Wang 2007 | Table 3, p. 4, row 1 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 |
|---|---|---|---|---|---|---|---|---|
| -20.9 | kJ/mol-atom | 0.05 | 3.5 (unknown, calibrated) | 3.5 | ||||
| -17.5 | kJ/mol-atom | 0.05 | 3.5 (unknown, calibrated) | 3.5 | ||||
| -20.1 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 |
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-aaaaaarm | -13.759 | -0.142607 | I4/mmm | 0 | 0 | no |
| OQMD | oqmd-17259 | -15.938 | -0.165181 | I4/mmm | 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
- Jingfang Wang, Wenxia Yuan, Min Li, Thermodynamic modeling of the Ga–N–Na system, Journal of Crystal Growth 307, 59-65 (2007). doi:10.1016/j.jcrysgro.2007.05.044