Fe2Ti: enthalpy of formation

39 accepted literature formation-enthalpy value(s) (experimental 10, model 20, DFT 6, unspecified 3); experimental median -25.4 kJ/mol-atom (n = 7); Materials Project -27.342 kJ/mol-atom (mp-aaaaadqk); OQMD -29.56 kJ/mol-atom (oqmd-1590944).

Systems: Fe–Ti

Literature values

Enthalpy of formation of Fe2Ti reported in the literature (39)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-27.6 kJ/mol-atom	Fe2Ti	1514	experimental		Fe–Ti	[1] Santhy 2021 cites Gachon 1983	Table 8, p. 8, row 9 report
-27.6 kJ/mol-atom ± 1	Fe2Ti	1514	experimental		Fe–Ti	[2] Jonsson 1998 cites Gachon 1981 doi	Table I, p. 2, row 7 report
-27.6 kJ/mol (basis unstated)	Fe2Ti	1514.15	experimental		Fe–Ti	[3] Wang 2011 cites Gachon 1983 doi	Table 4, p. 6, row 10 report
-27.6 kJ/mol-atom ± 1	Fe2Ti	1514	experimental		Fe–Ti	[4] Dumitrescu 1998 cites Gachon 1981 doi	Table 3, p. 4, row 22 report
-25.4 kJ/mol-atom ± 2	Fe2Ti	1413	experimental		Fe–Ti	[2] Jonsson 1998 cites Dinsdale 1981	Table I, p. 2, row 9 report
-25.4 kJ/mol-atom ± 2	Fe2Ti	1413	experimental		Fe–Ti	[4] Dumitrescu 1998 cites Dinsdale 1985	Table 3, p. 4, row 27 report
-25.394 kJ/mol (basis unstated)	Fe2Ti	1413.15	experimental		Fe–Ti	[3] Wang 2011 cites Dinsdale 1985	Table 4, p. 6, row 14 report
-25.39 kJ/mol-atom	Fe2Ti	1413	experimental		Fe–Ti	[1] Santhy 2021 cites Dinsdale 1985	Table 8, p. 8, row 6 report
-21.294 kJ/mol (basis unstated)	Fe2Ti	973.15	experimental		Fe–Ti	[3] Wang 2011 cites Dinsdale 1985	Table 4, p. 6, row 12 report
-21.29 kJ/mol-atom	Fe2Ti	973	experimental		Fe–Ti	[1] Santhy 2021 cites Dinsdale 1985	Table 8, p. 8, row 3 report
-34.52 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[4] Dumitrescu 1998 cites Haft 1994	Table 3, p. 4, row 31 report
-34.168 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[4] Dumitrescu 1998 cites Balasubramanian 1989	Table 3, p. 4, row 29 report
-33.93 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[4] Dumitrescu 1998 cites Jonsson 1998	Table 3, p. 4, row 32 report
-33.9 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[2] Jonsson 1998	Table I, p. 2, row 10 report
-31.84 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[4] Dumitrescu 1998 cites Rand 1998	Table 3, p. 4, row 30 report
-31.815 kJ/mol-atom	Fe2Ti	1514	model		Fe–Ti	[4] Dumitrescu 1998 cites Haft 1994	Table 3, p. 4, row 24 report
-31.513 kJ/mol-atom	Fe2Ti	1514	model		Fe–Ti	[4] Dumitrescu 1998 cites Jonsson 1998	Table 3, p. 4, row 25 report
-31.5 kJ/mol-atom	Fe2Ti	1514	model		Fe–Ti	[2] Jonsson 1998	Table I, p. 2, row 8 report
-30.13 kJ/mol-atom	Fe2Ti	0	model	FP method	Fe–Ti	[1] Santhy 2021	Table 8, p. 8, row 10 report
-29.752 kJ/mol-atom	Fe2Ti	1514	model		Fe–Ti	[4] Dumitrescu 1998 cites Rand 1998	Table 3, p. 4, row 23 report
-29.273 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[4] Dumitrescu 1998	Table 3, p. 4, row 33 report
-29.11 kJ/mol-atom	Fe2Ti	1514	model		Fe–Ti	[1] Santhy 2021	Table 8, p. 8, row 7 report
-28.42 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[1] Santhy 2021	Table 8, p. 8, row 4 report
-26.863 kJ/mol-atom	Fe2Ti	1514	model		Fe–Ti	[4] Dumitrescu 1998	Table 3, p. 4, row 26 report
-26.13 kJ/mol-atom	Fe2Ti	1514	model		Fe–Ti	[1] Santhy 2021	Table 8, p. 8, row 8 report
-26.01 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[1] Santhy 2021	Table 8, p. 8, row 5 report
-25 kJ/mol-atom	Fe2Ti	0	model	Miedema	Fe–Ti	[1] Santhy 2021 cites Miedema 1981	Table 8, p. 8, row 11 report
-22.4 kJ/mol-atom	Fe2Ti	973	model		Fe–Ti	[1] Santhy 2021	Table 8, p. 8, row 1 report
-21.26 kJ/mol-atom	Fe2Ti	973	model		Fe–Ti	[1] Santhy 2021	Table 8, p. 8, row 2 report
7.179 kJ/mol-atom	Fe2Ti	1413	model		Fe–Ti	[4] Dumitrescu 1998 cites Murray 1987	Table 3, p. 4, row 28 report
-30.131 kJ/mol-atom	Fe₂Ti	0	DFT	first-principles	Fe–Ti	[1] Santhy 2021	Table 5, p. 3, row 10 report
-29.817 kJ/mol-atom	Fe₂Ti	0	DFT	first-principles	Fe–Ti	[1] Santhy 2021	Table 5, p. 3, row 11 report
-27.134 kJ/mol-atom	Fe₂Ti	0	DFT	first-principles	Fe–Ti	[1] Santhy 2021	Table 5, p. 3, row 12 report
-23.678 kJ/mol-atom	Fe₂Ti	0	DFT	first-principles	Fe–Ti	[1] Santhy 2021	Table 5, p. 3, row 15 report
26.931 kJ/mol-atom	Fe₂Ti	0	DFT	first-principles	Fe–Ti	[1] Santhy 2021	Table 5, p. 3, row 13 report
37.039 kJ/mol-atom	Fe₂Ti	0	DFT	first-principles	Fe–Ti	[1] Santhy 2021	Table 5, p. 3, row 14 report
-34.3 kJ/mol (basis unstated)	Fe2Ti	1413.15	unspecified		Fe–Ti	[3] Wang 2011	Table 4, p. 6, row 13 report
-31.6 kJ/mol (basis unstated)	Fe2Ti	1514.15	unspecified		Fe–Ti	[3] Wang 2011	Table 4, p. 6, row 9 report
-30.8 kJ/mol (basis unstated)	Fe2Ti	973.15	unspecified		Fe–Ti	[3] Wang 2011	Table 4, p. 6, 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.

Uncertainty budget of the literature values of Fe2Ti
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-27.6	kJ/mol-atom		0.05	3.5 (unknown, calibrated)	3.5
-27.6	kJ/mol-atom	1	0.05	3.5 (unknown, calibrated)	3.5
-27.6	kJ/mol (basis unstated)		5.000e-4	10.5 (unknown, calibrated)	10.5
-27.6	kJ/mol-atom	1	0.05	3.5 (unknown, calibrated)	3.5
-25.4	kJ/mol-atom	2	0.05	3.5 (unknown, calibrated)	3.5
-25.4	kJ/mol-atom	2	0.05	3.5 (unknown, calibrated)	3.5
-25.394	kJ/mol (basis unstated)		5.000e-4	10.5 (unknown, calibrated)	10.5
-25.39	kJ/mol-atom		0.005	3.5 (unknown, calibrated)	3.5
-21.294	kJ/mol (basis unstated)		5.000e-4	10.5 (unknown, calibrated)	10.5
-21.29	kJ/mol-atom		0.005	3.5 (unknown, calibrated)	3.5
-34.52	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-34.168	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-33.93	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-33.9	kJ/mol-atom		0.05	3.9 (model_calculated, calibrated)	3.9
-31.84	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-31.815	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-31.513	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-31.5	kJ/mol-atom		0.05	3.9 (model_calculated, calibrated)	3.9
-30.13	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-29.752	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-29.273	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-29.11	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-28.42	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-26.863	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-26.13	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-26.01	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-25	kJ/mol-atom		0.5	3.9 (model_calculated, calibrated)	3.9
-22.4	kJ/mol-atom		0.05	3.9 (model_calculated, calibrated)	3.9
-21.26	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
7.179	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-30.131	kJ/mol-atom		5.000e-4	3.929 (dft, calibrated)	3.929
-29.817	kJ/mol-atom		5.000e-4	3.929 (dft, calibrated)	3.929
-27.134	kJ/mol-atom		5.000e-4	3.929 (dft, calibrated)	3.929
-23.678	kJ/mol-atom		5.000e-4	3.929 (dft, calibrated)	3.929
26.931	kJ/mol-atom		5.000e-4	3.929 (dft, calibrated)	3.929
37.039	kJ/mol-atom		5.000e-4	3.929 (dft, calibrated)	3.929
-34.3	kJ/mol (basis unstated)		5.000e-4	10.5 (unknown, calibrated)	10.5
-31.6	kJ/mol (basis unstated)		5.000e-4	10.5 (unknown, calibrated)	10.5
-30.8	kJ/mol (basis unstated)		5.000e-4	10.5 (unknown, calibrated)	10.5

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 Fe2Ti
Source	Entry	kJ/mol-atom	eV/atom	Space group	E above hull (kJ/mol-atom)	E above hull (eV/atom)	Theoretical
Materials Project	mp-aaaaadqk	-27.342	-0.283385	P6_3/mmc	0	0	no
OQMD	oqmd-1590944	-29.56	-0.306365	Fd-3m	0	0	yes
OQMD	oqmd-18688	-28.736	-0.297833	P63/mmc	0.8232	0.0085	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

K. Santhy, K.C. Hari Kumar, Thermodynamic modelling of magnetic laves phase in Fe–Ti system using first principle method, Intermetallics 128, 106978 (2021). doi:10.1016/j.intermet.2020.106978
Stefan Jonsson, Assessment of the Fe-Ti system, Metall Mater Trans B 29, 361-370 (1998). doi:10.1007/s11663-998-0113-z
C.P. Wang, J.P. Zheng, Y. Yu, H.F. Hu, X.J. Liu, Experimental investigation and thermodynamic calculation of the phase equilibria in the Fe–Nb–Ti ternary system, Materials Chemistry and Physics 130, 806-814 (2011). doi:10.1016/j.matchemphys.2011.07.071
L. F. S. Dumitrescu, M. Hillert, N. Sounders, Comparison of Fe-Ti assessments, JPE 19, 441-448 (1998). doi:10.1361/105497198770341923

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}
}