Ge3Hf5: enthalpy of formation
3 accepted literature formation-enthalpy value(s) (experimental 1, model 1, DFT 1); experimental median -42.31 kJ/mol-atom (n = 1); Materials Project -65.411 kJ/mol-atom (mp-aaaaacox); OQMD -65.437 kJ/mol-atom (oqmd-1340141).
Systems: Ge–Hf
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -42.31 kJ/mol-atom ± 4.1 | Hf5Ge3 | 298.15 | experimental | Ge–Hf | [1] Tang 2014 cites Golutvin 1979 | Table 2, p. 3, row 7 report | ||
| -64.448 kJ/mol-atom | Hf5Ge3 | 298.15 | model | modeling | Ge–Hf | [1] Tang 2014 | Table 2, p. 3, row 9 report | |
| -65.588 kJ/mol-atom | Hf5Ge3 | 0 | DFT | FP | Ge–Hf | [1] Tang 2014 | Table 2, p. 3, row 8 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 |
|---|---|---|---|---|---|---|---|---|
| -42.31 | kJ/mol-atom | 4.1 | 0.005 | 3.5 (unknown, calibrated) | 4.1 | |||
| -64.448 | kJ/mol-atom | 5.000e-4 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -65.588 | 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-aaaaacox | -65.411 | -0.677936 | P6_3/mcm | 0.2237 | 0.0023 | no |
| OQMD | oqmd-1340141 | -65.437 | -0.67821 | P63/mcm | 0.3139 | 0.0033 | 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
- Ying Tang, Biao Hu, Jiong Wang, Yong Du, Kaiming Cheng, Dandan Liu et al., Experimental investigation and thermodynamic assessment of the Hf–Ge system, J Mater Sci 49, 1306-1316 (2014). doi:10.1007/s10853-013-7814-7