Si5V6: enthalpy of formation
9 accepted literature formation-enthalpy value(s) (experimental 2, model 4, DFT 1, unspecified 2); experimental median -50.7 kJ/mol-atom (n = 2); Materials Project -49.196 kJ/mol-atom (mp-aaaaablo); OQMD -51.21 kJ/mol-atom (oqmd-31070).
Systems: Si–V
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -50.7 kJ/mol-atom ± 2 | V6Si5 | 298.15 | experimental | emf measurement | Si–V | [1] Zhang 2008 cites Eremenko 1976 | Table 2, p. 3, row 6 report | |
| -50.7 kJ/mol-atom ± 2 | V6Si5 | 298.15 | experimental | Si–V | [2] Broz 2013 cites Eremenko 1975 | Table 2, p. 6, row 24 report | ||
| -52.8 kJ/mol-atom | V6Si5 | 0 | model | Si–V | [2] Broz 2013 cites Zhang 2008 doi | Table 2, p. 6, row 22 report | ||
| -51.2 kJ/mol-atom | V6Si5 | model | Si–V | [2] Broz 2013 cites Chen 2006 doi | Table 2, p. 6, row 26 report | |||
| -48.13 kJ/mol-atom | V6Si5 | 298.15 | model | Miedema model | Si–V | [1] Zhang 2008 cites Chen 2006 doi | Table 2, p. 3, row 17 report | |
| -48.1 kJ/mol-atom | V6Si5 | model | Si–V | [2] Broz 2013 cites Chen 2006 doi | Table 2, p. 6, row 25 report | |||
| -51.22 kJ/mol-atom | V6Si5 | 298.15 | DFT | First-principles | Si–V | [1] Zhang 2008 cites Zhang 2007 doi | Table 2, p. 3, row 21 report | |
| -52.7 kJ/mol-atom | V6Si5 | 0 | unspecified | Si–V | [2] Broz 2013 | Table 2, p. 6, row 23 report | ||
| -44.1 kJ/mol-atom | V6Si5 | 0 | unspecified | Si–V | [2] Broz 2013 | Table 2, p. 6, row 21 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 |
|---|---|---|---|---|---|---|---|---|
| -50.7 | kJ/mol-atom | 2 | 0.05 | 4.6 (emf, cleaned_below_threshold) | 4.6 | |||
| -50.7 | kJ/mol-atom | 2 | 0.05 | 3.5 (unknown, calibrated) | 3.5 | |||
| -52.8 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -51.2 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -48.13 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -48.1 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -51.22 | kJ/mol-atom | 0.005 | 9.966 (dft, calibrated) | 9.966 | ||||
| -52.7 | kJ/mol-atom | 0.05 | 3.5 (unknown, calibrated) | 3.5 | ||||
| -44.1 | kJ/mol-atom | 0.05 | 3.5 (unknown, calibrated) | 3.5 |
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-aaaaablo | -49.196 | -0.509879 | Ibam | 1.3649 | 0.0141 | no |
| OQMD | oqmd-31070 | -51.21 | -0.530758 | Ibam | 1.4495 | 0.015 | 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
- Chao Zhang, Yong Du, Wei Xiong, Honghui Xu, Philip Nash, Yifang Ouyang et al., Thermodynamic modeling of the V–Si system supported by key experiments, Calphad 32, 320-325 (2008). doi:10.1016/j.calphad.2007.12.005
- P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013). doi:10.1016/j.jssc.2012.12.003