Ni2Tb: enthalpy of formation
5 accepted literature formation-enthalpy value(s) (experimental 1, model 3, DFT 1); experimental median -40 kJ/mol-atom (n = 1); Materials Project -41.721 kJ/mol-atom (mp-aaaaaakq); OQMD -20.948 kJ/mol-atom (oqmd-17694).
Systems: Ni–Tb
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -40 kJ/mol-atom | TbNi2 | 298.15 | experimental | Calorimetry | Ni–Tb | [1] Rahou 2024 cites Delsante 2013 doi | Table 4, p. 7, row 16 report | |
| -51 kJ/mol-atom | TbNi2 | model | CALPHAD | Ni–Tb | [1] Rahou 2024 cites Rong 2004 doi | Table 4, p. 7, row 18 report | ||
| -46.4 kJ/mol-atom | TbNi2 | model | Miedema model | Ni–Tb | [1] Rahou 2024 cites Niessen 1983 doi | Table 4, p. 7, row 17 report | ||
| -39.7 kJ/mol-atom | TbNi2 | model | CALPHAD | Ni–Tb | [1] Rahou 2024 | Table 4, p. 7, row 15 report | ||
| -41.7 kJ/mol-atom | TbNi2 | 0 | DFT | Ab initio | Ni–Tb | [1] Rahou 2024 | Table 4, p. 7, row 14 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 |
|---|---|---|---|---|---|---|---|---|
| -40 | kJ/mol-atom | 0.05 | 3.2 (solution_reaction_calorimetry, calibrated) | 3.2 | ||||
| -51 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -46.4 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -39.7 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -41.7 | kJ/mol-atom | 0.05 | 3.929 (dft, calibrated) | 3.929 |
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-aaaaaakq | -41.721 | -0.432406 | Fd-3m | 0 | 0 | no |
| OQMD | oqmd-17694 | -20.948 | -0.217115 | Fd-3m | 0 | 0 | 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
- Z. Rahou, D. Moustaine, Y. Ben-Ali, A. Hallaoui, CALPHAD-Based Thermodynamic Reassessment of Tb-Ni Binary System Supported by Ab-Initio Calculations, J. Phase Equilib. Diffus. 45, 75-85 (2024). doi:10.1007/s11669-024-01089-9