Si2V: enthalpy of formation

19 accepted literature formation-enthalpy value(s) (experimental 9, model 7, DFT 2, unspecified 1); experimental median -41.67 kJ/mol-atom (n = 9); Materials Project -42.137 kJ/mol-atom (mp-aaaaapvz); OQMD -45.955 kJ/mol-atom (oqmd-16520).

Systems: Si–V

Literature values

Enthalpy of formation of Si2V reported in the literature (19)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-44.43 kJ/mol-atom ± 1	VSi2	298.15	experimental	Fluorine bomb calorimetry	Si–V	[1] Zhang 2008 cites OHare 1999 doi	Table 2, p. 3, row 13 report
-44.4 kJ/mol-atom ± 1	VSi2	298.15	experimental		Si–V	[2] Broz 2013 cites P 1999	Table 2, p. 6, row 39 report
-44.4 kJ/mol-atom ± 1	Si2V	298.15	experimental	Exp	Si–V	[3] Luo 2018 cites OHare 2000	Table 3, p. 5, row 24 report
-41.7 kJ/mol-atom ± 3	VSi2	298.15	experimental		Si–V	[2] Broz 2013 cites Gorelkin 1971	Table 2, p. 6, row 36 report
-41.67 kJ/mol-atom ± 3	VSi2	298.15	experimental	Direct reaction calorimetry	Si–V	[1] Zhang 2008 cites Gorelkin 1971	Table 2, p. 3, row 1 report
-41.5 kJ/mol-atom ± 2	VSi2	298.15	experimental	emf measurement	Si–V	[1] Zhang 2008 cites Eremenko 1976	Table 2, p. 3, row 4 report
-41.5 kJ/mol-atom ± 2	VSi2	298.15	experimental		Si–V	[2] Broz 2013 cites Eremenko 1975	Table 2, p. 6, row 37 report
-39.7 kJ/mol-atom ± 1	VSi2	298.15	experimental		Si–V	[2] Broz 2013 cites Storms 1985	Table 2, p. 6, row 38 report
-39.67 kJ/mol-atom ± 1	VSi2	298.15	experimental	Knudsen cell mass spectrometry	Si–V	[1] Zhang 2008 cites Storms 1985	Table 2, p. 3, row 8 report
-54.674 kJ/mol-atom	Si2V		model		Si–V	[3] Luo 2018	Table 3, p. 5, row 23 report
-54.1 kJ/mol-atom	Si2V		model	Calphad	Si–V	[3] Luo 2018 cites Zhang 2008 doi	Table 3, p. 5, row 21 report
-54.1 kJ/mol-atom	VSi2	0	model		Si–V	[2] Broz 2013 cites Zhang 2008 doi	Table 2, p. 6, row 42 report
-45.9 kJ/mol-atom	VSi2		model		Si–V	[2] Broz 2013 cites Zhang 2007 doi	Table 2, p. 6, row 41 report
-29 kJ/mol-atom	VSi2		model		Si–V	[2] Broz 2013 cites Chen 2006 doi	Table 2, p. 6, row 40 report
-29 kJ/mol-atom	VSi2	298.15	model	Miedema model	Si–V	[1] Zhang 2008 cites Chen 2006 doi	Table 2, p. 3, row 15 report
-8.285 kJ/mol-atom	Si2V		model		Si–V	[3] Luo 2018	Table 3, p. 5, row 25 report
-47 kJ/mol-atom	Si2V	0	DFT	DFT	Si–V	[3] Luo 2018 cites Broz 2013 doi	Table 3, p. 5, row 22 report
-45.91 kJ/mol-atom	VSi2	298.15	DFT	First-principles	Si–V	[1] Zhang 2008 cites Zhang 2007 doi	Table 2, p. 3, row 19 report
-47 kJ/mol-atom	VSi2	0	unspecified		Si–V	[2] Broz 2013	Table 2, p. 6, row 35 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.

Uncertainty budget of the literature values of Si2V
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-44.43	kJ/mol-atom	1	0.005	1 (combustion_calorimetry, cleaned_below_threshold)	1
-44.4	kJ/mol-atom	1	0.05	3.5 (unknown, calibrated)	3.5
-44.4	kJ/mol-atom	1	0.05	4.1 (experimental_unspecified, cleaned_below_threshold)	4.1
-41.7	kJ/mol-atom	3	0.05	3.5 (unknown, calibrated)	3.5
-41.67	kJ/mol-atom	3	0.005	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-41.5	kJ/mol-atom	2	0.05	4.6 (emf, cleaned_below_threshold)	4.6
-41.5	kJ/mol-atom	2	0.05	3.5 (unknown, calibrated)	3.5
-39.7	kJ/mol-atom	1	0.05	3.5 (unknown, calibrated)	3.5
-39.67	kJ/mol-atom	1	0.005	4.2 (kems_vapour, calibrated)	4.2
-54.674	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-54.1	kJ/mol-atom		0.05	3.9 (model_calculated, calibrated)	3.9
-54.1	kJ/mol-atom		0.05	3.9 (model_calculated, calibrated)	3.9
-45.9	kJ/mol-atom		0.05	3.9 (model_calculated, calibrated)	3.9
-29	kJ/mol-atom		0.05	3.9 (model_calculated, calibrated)	3.9
-29	kJ/mol-atom		0.05	3.9 (model_calculated, calibrated)	3.9
-8.285	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-47	kJ/mol-atom		0.05	9.966 (dft, calibrated)	9.966
-45.91	kJ/mol-atom		0.005	9.966 (dft, calibrated)	9.966
-47	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.

DFT formation energy of Si2V
Source	Entry	kJ/mol-atom	eV/atom	Space group	E above hull (kJ/mol-atom)	E above hull (eV/atom)	Theoretical
Materials Project	mp-aaaaapvz	-42.137	-0.436721	P6_222	0	0	no
OQMD	oqmd-16520	-45.955	-0.476293	P6422	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

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
Qun Luo, Kang Li, Qian Li, Thermodynamic investigation of phase equilibria in Al–Si–V system, Journal of Materials Science & Technology 34, 1592-1601 (2018). doi:10.1016/j.jmst.2018.01.004

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735569
R. Arróyave, J. Saal, D. Shin, ORCHID-Parity: DFT-vs-experiment formation-enthalpy benchmark (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735943
R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23736065

Also cite the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002, https://doi.org/10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501, https://doi.org/10.1007/s11837-013-0755-4 and S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010, https://doi.org/10.1038/npjcompumats.2015.10 (CC BY 4.0); G. Kim, S. V. Meschel, P. Nash, W. Chen, Experimental formation enthalpies for intermetallic phases and other inorganic compounds, Scientific Data 4 (2017) 170162, https://doi.org/10.1038/sdata.2017.162; B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, https://doi.org/10.1016/j.calphad.2025.102833 (CC BY 4.0), and the original assessment named in each file. Version 1, machine-extracted: values were read by language-model readers constrained to quote their source and checked automatically, and the release was then audited on the printed pages by adversarial audits, an independent second review of fit-facing records and a preliminary human review of a frozen sample. Flags such as accepted and ESPEI-ready record screening results, not certification; known issues are listed in the release notes.

@misc{orchid_literature_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735569},
  url       = {https://doi.org/10.5281/zenodo.23735569},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_dft_benchmark_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Parity: DFT-vs-experiment formation-enthalpy benchmark}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735943},
  url       = {https://doi.org/10.5281/zenodo.23735943},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_data_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID data: umbrella record of the ORCHID datasets}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23736065},
  url       = {https://doi.org/10.5281/zenodo.23736065},
  note      = {Version 1, machine-extracted}
}