Ba2Ge: enthalpy of formation
2 accepted literature formation-enthalpy value(s) (model 1, DFT 1); Materials Project -47.487 kJ/mol-atom (mp-aaaaaupm); OQMD -47.179 kJ/mol-atom (oqmd-1343651).
Systems: Ba–Ge
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -51.13 kJ/mol-atom | Ba2Ge | model | CALPHAD | Ba–Ge | [1] Benhafid 2019 | Table 3, p. 4, row 20 report | ||
| -50.129 kJ/mol-atom | Ba2Ge | 0 | DFT | Ab-initio | Ba–Ge | [1] Benhafid 2019 | Table 3, p. 4, row 19 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 |
|---|---|---|---|---|---|---|---|---|
| -51.13 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -50.129 | 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-aaaaaupm | -47.487 | -0.492168 | Pnma | 0 | 0 | no |
| OQMD | oqmd-1343651 | -47.179 | -0.48898 | Pnma | 0 | 0 | yes |
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
- 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