# TiB2: enthalpy of formation > Enthalpy of formation of TiB2: 20 literature value(s) with sources, pages and quotes, from ORCHID. HTML: https://data.orchid-project.org/compounds/TiB2.html · Markdown: https://data.orchid-project.org/compounds/TiB2.md 20 accepted literature formation-enthalpy value(s) (experimental 8, model 1, DFT 11). Systems: [B–Ti](https://data.orchid-project.org/systems/B-TI.html) ## Literature values Table: Enthalpy of formation of TiB2 reported in the literature (20) | Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote | |---:|---|---:|---|---|---|---|---|---| | -323.8 kJ/mol (basis unstated) | TiB2 | 298.15 | experimental | X-ray diffraction | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [1] Ma 2004; _cites Guzman 1995_ [doi](https://doi.org/10.1016/0042-207x%2895%2900080-1) | Table 3, p. 4, row 8; `ORC-QPG6PXYTBW.13beb3` | | | -319.788 kJ/mol (basis unstated) | TiB2 | 298.15 | experimental | X-ray diffraction | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [1] Ma 2004; _cites Akhachinskij 1975_ | Table 3, p. 4, row 12; `ORC-HNJGZWKT7M.4f020f` | | | -314.754 kJ/mol (basis unstated) ± 17.556 | TiB2 | 298.15 | experimental | Second law analysis | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [1] Ma 2004; _cites Yurick 1980_ | Table 3, p. 4, row 6; `ORC-UTFN4L7VVT.88d3de` | | | -305.34 kJ/mol (basis unstated) ± 6.72 | TiB2 | 298.15 | experimental | Third law analysis | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [1] Ma 2004; _cites Yurick 1980_ | Table 3, p. 4, row 7; `ORC-QAIEJY5PLE.87500e` | | | -300.96 kJ/mol (basis unstated) | TiB2 | 298.15 | experimental | Mass spectrometer | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [1] Ma 2004; _cites Schissel 1959_ | Table 3, p. 4, row 13; `ORC-QPEG3L2UE6.826383` | | | -298.2 kJ/mol (basis unstated) | TiB2 | 298.15 | experimental | X-ray diffraction | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [1] Ma 2004; _cites Brewer 1955_ [doi](https://doi.org/10.1149/1.2430108) | Table 3, p. 4, row 9; `ORC-GDEHMERE2N.5ceeec` | | | -292.6 kJ/mol (basis unstated) | TiB2 | 298.15 | experimental | X-ray diffraction | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [1] Ma 2004; _cites Williams 1961_ [doi](https://doi.org/10.1021/j100829a025) | Table 3, p. 4, row 11; `ORC-LRSVCUE2OP.0741f6` | | | -217.32 kJ/mol (basis unstated) | TiB2 | 298.15 | experimental | Mass spectrometer | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [1] Ma 2004; _cites Schissel 1962_ [doi](https://doi.org/10.1021/j100814a027) | Table 3, p. 4, row 10; `ORC-GFIVUOES6R.43fb3d` | | | -109.7 kJ/mol (basis unstated) | TiB2 | | model | | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009; _cites Witusiewicz 2008_ [doi](https://doi.org/10.1016/j.jallcom.2007.02.030) | Table 3, p. 6, row 10; `ORC-KY5I2XDXKX.14565f` | | | -105.2 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 9; `ORC-UB7DRKET3L.371556` | | | -83.1 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 8; `ORC-UI5E6TR7KM.1ef761` | | | -78.9 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 11; `ORC-LTAEBAXAWN.5f65c5` | | | -68.7 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 12; `ORC-UU5R7M4IN3.9997ab` | | | -68.2 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 7; `ORC-4ULIDESGEF.1b9e6e` | | | -56.6 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 13; `ORC-PKGEULRMEB.314450` | | | -46.4 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 14; `ORC-JLUPVVRQUU.ecc2a4` | | | -32.1 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 6; `ORC-YGN43ZTDKN.e65f5a` | | | -21.7 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 15; `ORC-OAP5KRTSD6.2f3b9b` | | | 35 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 5; `ORC-56Q6CELU3R.5c5328` | | | 68.1 kJ/mol (basis unstated) | TiB2 | 0 | DFT | First principles | [B–Ti](https://data.orchid-project.org/systems/B-TI.html) | [2] Nakama 2009 | Table 3, p. 6, row 16; `ORC-MSD3PBGDPM.ac36b6` | | ### Uncertainty budget Components kept separate, in the value's unit (literature [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md), [UNCERTAINTY_CALIBRATION.md](https://data.orchid-project.org/literature/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. Table: Uncertainty budget of the literature values of TiB2 | Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | 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 1. 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](https://doi.org/10.1016/j.jallcom.2003.09.017) 2. Yu Nakama, Hiroshi Ohtani, Mitsuhiro Hasebe, Thermodynamic Analysis of the Nb–Ti–B Ternary Phase Diagram, Mater. Trans. 50, 984-993 (2009). [doi:10.2320/matertrans.mc200820](https://doi.org/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). https://doi.org/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). https://doi.org/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). https://doi.org/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. ```bibtex @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} } ``` --- Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite ORCHID ([CITATION.cff](https://data.orchid-project.org/CITATION.cff)) and the original sources. Quotes are short excerpts kept so that each value can be checked; they remain under the publishers' copyright and are not relicensed. Source papers, page images and full text are not redistributed. Field reference: [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt). Found an error? The report link of a value (Markdown: its id, ORC-..., in the Location column) opens a pre-filled GitHub issue, https://github.com/orchid-calphad/orchid-data/issues/new?template=report-value-error.yml&record_id=\, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).