Hf2Ni7: enthalpy of formation
3 accepted literature formation-enthalpy value(s) (model 2, DFT 1); Materials Project -44.758 kJ/mol-atom (mp-aaacqpve); OQMD -45.225 kJ/mol-atom (oqmd-1437798).
Systems: Hf–Ni
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -45.18 kJ/mol-atom | Ni7Hf2 | 298.15 | model | Hf–Ni | [1] Ross 2018 | Table 1, p. 4, row 4 report | ||
| -45.1 kJ/mol-atom | Ni7Hf2 | 298.15 | model | Hf–Ni | [1] Ross 2018 cites Berche 2016 doi | Table 1, p. 4, row 5 report | ||
| -45.1 kJ/mol (basis unstated) | Hf2Ni7 | 0 | DFT | DFT | Hf–Ni | [2] Berche 2016 | Table 2, p. 4, row 11 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 |
|---|---|---|---|---|---|---|---|---|
| -45.18 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -45.1 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -45.1 | kJ/mol (basis unstated) | 0.05 | 35.36 (dft, calibrated) | 35.36 |
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-aaacqpve | -44.758 | -0.463886 | C2/m | 1.3911 | 0.0144 | yes |
| OQMD | oqmd-1437798 | -45.225 | -0.468721 | C2/m | 1.4515 | 0.015 | 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
- A.J. Ross, T. Gheno, P.K. Ray, M.J. Kramer, X.L. Liu, G. Lindwall et al., A first-principles based description of the Hf-Ni system supported by high-temperature synchrotron experiments, Thermochimica Acta 668, 142-151 (2018). doi:10.1016/j.tca.2018.08.011
- A. Berche, J.C. Tédenac, P. Jund, Phase diagram and enthalpy of formation of Hf-Ni-Sn, Computational Materials Science 125, 271-277 (2016). doi:10.1016/j.commatsci.2016.08.042