Ge4Y5: enthalpy of formation
3 accepted literature formation-enthalpy value(s) (experimental 1, model 2); experimental median -102.5 kJ/mol-atom (n = 1); Materials Project -84.954 kJ/mol-atom (mp-aaaaattw); OQMD -85.431 kJ/mol-atom (oqmd-124138).
Systems: Ge–Y
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -102.5 kJ/mol-atom ± 5.5 | Ge4Y5 | 870 | experimental | EMF | Ge–Y | [1] Idbenali 2013 cites Polotskaya 1996 doi | Table 4, p. 5, row 17 report | |
| -109.55 kJ/mol-atom | Ge4Y5 | 298.15 | model | Optimization | Ge–Y | [1] Idbenali 2013 | Table 4, p. 5, row 19 report | |
| -94.131 kJ/mol-atom | Ge4Y5 | 870 | model | Optimization | Ge–Y | [1] Idbenali 2013 | Table 4, p. 5, row 18 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 |
|---|---|---|---|---|---|---|---|---|
| -102.5 | kJ/mol-atom | 5.5 | 0.05 | 4.6 (emf, cleaned_below_threshold) | 5.5 | |||
| -109.55 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -94.131 | kJ/mol-atom | 5.000e-4 | 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-aaaaattw | -84.954 | -0.88049 | Pnma | 0 | 0 | no |
| OQMD | oqmd-124138 | -85.431 | -0.885429 | Pnma | 0.4888 | 0.0051 | 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
- Mohamed Idbenali, Colette Servant, Thermodynamic optimization of the germanium–yttrium system, J Therm Anal Calorim 111, 911-916 (2013). doi:10.1007/s10973-012-2271-0