Al5Ba3: enthalpy of formation
3 accepted literature formation-enthalpy value(s) (model 2, DFT 1); Materials Project -22.211 kJ/mol-atom (mp-aaaaaakb); OQMD -22.16 kJ/mol-atom (oqmd-26824).
Systems: Al–Ba
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -52.72 kJ/mol-atom | Al5Ba3 | model | Al–Ba | [1] Azza 2017 | Table 4, p. 6, row 7 report | |||
| -23.954 kJ/mol-atom | Al5Ba3 | model | CALPHAD | Al–Ba | [2] Benhafid 2019 | Table 3, p. 4, row 14 report | ||
| -23.356 kJ/mol-atom | Al5Ba3 | 0 | DFT | Ab-initio | Al–Ba | [2] Benhafid 2019 | Table 3, p. 4, row 13 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 |
|---|---|---|---|---|---|---|---|---|
| -52.72 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -23.954 | kJ/mol-atom | 5.000e-4 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -23.356 | kJ/mol-atom | 5.000e-4 | 8.395 (dft, calibrated) | 8.395 |
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-aaaaaakb | -22.211 | -0.230206 | P6_3/mmc | 0.7137 | 0.0074 | no |
| OQMD | oqmd-26824 | -22.16 | -0.229673 | P63/mmc | 0.3765 | 0.0039 | 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
- H. Azza, N. Selhaoui, K. Achgar, Thermodynamic description of the aluminum-barium phase diagram, Eur. Phys. J. Spec. Top. 226, 1143-1150 (2017). doi:10.1140/epjst/e2016-60183-4
- R. Benhafid, A. Belgacem Bouzida, Y. Djaballah, A. Candan, A. İyigör, G. Uğur, Thermodynamic Modeling of the Al-Ba and Ba-Ge Systems Supported by First-Principles Calculations, J. Phase Equilib. Diffus. 40, 195-205 (2019). doi:10.1007/s11669-019-00714-2