TiB2: enthalpy of formation

20 accepted literature formation-enthalpy value(s) (experimental 8, model 1, DFT 11).

Systems: B–Ti

Literature values

Enthalpy of formation of TiB2 reported in the literature (20)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-323.8 kJ/mol (basis unstated)	TiB2	298.15	experimental	X-ray diffraction	B–Ti	[1] Ma 2004 cites Guzman 1995 doi	Table 3, p. 4, row 8 report
-319.788 kJ/mol (basis unstated)	TiB2	298.15	experimental	X-ray diffraction	B–Ti	[1] Ma 2004 cites Akhachinskij 1975	Table 3, p. 4, row 12 report
-314.754 kJ/mol (basis unstated) ± 17.556	TiB2	298.15	experimental	Second law analysis	B–Ti	[1] Ma 2004 cites Yurick 1980	Table 3, p. 4, row 6 report
-305.34 kJ/mol (basis unstated) ± 6.72	TiB2	298.15	experimental	Third law analysis	B–Ti	[1] Ma 2004 cites Yurick 1980	Table 3, p. 4, row 7 report
-300.96 kJ/mol (basis unstated)	TiB2	298.15	experimental	Mass spectrometer	B–Ti	[1] Ma 2004 cites Schissel 1959	Table 3, p. 4, row 13 report
-298.2 kJ/mol (basis unstated)	TiB2	298.15	experimental	X-ray diffraction	B–Ti	[1] Ma 2004 cites Brewer 1955 doi	Table 3, p. 4, row 9 report
-292.6 kJ/mol (basis unstated)	TiB2	298.15	experimental	X-ray diffraction	B–Ti	[1] Ma 2004 cites Williams 1961 doi	Table 3, p. 4, row 11 report
-217.32 kJ/mol (basis unstated)	TiB2	298.15	experimental	Mass spectrometer	B–Ti	[1] Ma 2004 cites Schissel 1962 doi	Table 3, p. 4, row 10 report
-109.7 kJ/mol (basis unstated)	TiB2		model		B–Ti	[2] Nakama 2009 cites Witusiewicz 2008 doi	Table 3, p. 6, row 10 report
-105.2 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 9 report
-83.1 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 8 report
-78.9 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 11 report
-68.7 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 12 report
-68.2 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 7 report
-56.6 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 13 report
-46.4 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 14 report
-32.1 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 6 report
-21.7 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 15 report
35 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 5 report
68.1 kJ/mol (basis unstated)	TiB2	0	DFT	First principles	B–Ti	[2] Nakama 2009	Table 3, p. 6, row 16 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 TiB2
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-323.8	kJ/mol (basis unstated)		5.000e-4	10.5 (equilibration_other, calibrated)	10.5
-319.788	kJ/mol (basis unstated)		5.000e-4	10.5 (equilibration_other, calibrated)	10.5
-314.754	kJ/mol (basis unstated)	17.56	5.000e-4	9 (kems_vapour_second_law, prior)	17.56
-305.34	kJ/mol (basis unstated)	6.72	5.000e-4	6 (kems_vapour_third_law, prior)	6.72
-300.96	kJ/mol (basis unstated)		5.000e-4	12.6 (kems_vapour, calibrated)	12.6
-298.2	kJ/mol (basis unstated)		5.000e-4	10.5 (equilibration_other, calibrated)	10.5
-292.6	kJ/mol (basis unstated)		5.000e-4	10.5 (equilibration_other, calibrated)	10.5
-217.32	kJ/mol (basis unstated)		5.000e-4	12.6 (kems_vapour, calibrated)	12.6
-109.7	kJ/mol (basis unstated)		0.05	11.7 (model_calculated, calibrated)	11.7
-105.2	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
-83.1	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
-78.9	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
-68.7	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
-68.2	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
-56.6	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
-46.4	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
-32.1	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
-21.7	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
35	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9
68.1	kJ/mol (basis unstated)		0.05	29.9 (dft, calibrated)	29.9

Sources

Xiaoyan Ma, Changrong Li, Zhenmin Du, Weijing Zhang, Thermodynamic assessment of the Ti–B system, Journal of Alloys and Compounds 370, 149-158 (2004). doi:10.1016/j.jallcom.2003.09.017
Yu Nakama, Hiroshi Ohtani, Mitsuhiro Hasebe, Thermodynamic Analysis of the Nb&ndash;Ti&ndash;B Ternary Phase Diagram, Mater. Trans. 50, 984-993 (2009). doi:10.2320/matertrans.mc200820

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}
}