# Si2V: enthalpy of formation > Enthalpy of formation of Si2V: 19 literature value(s) with sources, pages and quotes and DFT values (Materials Project / OQMD), from ORCHID. HTML: https://data.orchid-project.org/compounds/Si2V.html · Markdown: https://data.orchid-project.org/compounds/Si2V.md 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](https://data.orchid-project.org/systems/SI-V.html) ## Literature values Table: Enthalpy of formation of Si2V reported in the literature (19) | Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote | |---:|---|---:|---|---|---|---|---|---| | -44.43 kJ/mol-atom ± 1 | VSi2 | 298.15 | experimental | Fluorine bomb calorimetry | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [1] Zhang 2008; _cites OHare 1999_ [doi](https://doi.org/10.1006/jcht.1999.0579) | Table 2, p. 3, row 13; `ORC-TN3VW5X7D4` | | | -44.4 kJ/mol-atom ± 1 | VSi2 | 298.15 | experimental | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [2] Broz 2013; _cites P 1999_ | Table 2, p. 6, row 39; `ORC-S6OKYNP3SZ.f8c408` | | | -44.4 kJ/mol-atom ± 1 | Si2V | 298.15 | experimental | Exp | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [3] Luo 2018; _cites OHare 2000_ | Table 3, p. 5, row 24; `ORC-YYTBKWC54S` | | | -41.7 kJ/mol-atom ± 3 | VSi2 | 298.15 | experimental | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [2] Broz 2013; _cites Gorelkin 1971_ | Table 2, p. 6, row 36; `ORC-XZLTNIIPM3.9ff47c` | | | -41.67 kJ/mol-atom ± 3 | VSi2 | 298.15 | experimental | Direct reaction calorimetry | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [1] Zhang 2008; _cites Gorelkin 1971_ | Table 2, p. 3, row 1; `ORC-EVKJ5NDESF` | | | -41.5 kJ/mol-atom ± 2 | VSi2 | 298.15 | experimental | emf measurement | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [1] Zhang 2008; _cites Eremenko 1976_ | Table 2, p. 3, row 4; `ORC-SHZN2FNXY6` | | | -41.5 kJ/mol-atom ± 2 | VSi2 | 298.15 | experimental | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [2] Broz 2013; _cites Eremenko 1975_ | Table 2, p. 6, row 37; `ORC-WLDYUZIK3T.d8121c` | | | -39.7 kJ/mol-atom ± 1 | VSi2 | 298.15 | experimental | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [2] Broz 2013; _cites Storms 1985_ | Table 2, p. 6, row 38; `ORC-S2UGGDAQ7Q.ef55e3` | | | -39.67 kJ/mol-atom ± 1 | VSi2 | 298.15 | experimental | Knudsen cell mass spectrometry | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [1] Zhang 2008; _cites Storms 1985_ | Table 2, p. 3, row 8; `ORC-YC3TG34YZ3` | | | -54.674 kJ/mol-atom | Si2V | | model | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [3] Luo 2018 | Table 3, p. 5, row 23; `ORC-MYXDZSOOKG` | | | -54.1 kJ/mol-atom | Si2V | | model | Calphad | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [3] Luo 2018; _cites Zhang 2008_ [doi](https://doi.org/10.1016/j.calphad.2007.12.005) | Table 3, p. 5, row 21; `ORC-2YCSLZ6MEB` | | | -54.1 kJ/mol-atom | VSi2 | 0 | model | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [2] Broz 2013; _cites Zhang 2008_ [doi](https://doi.org/10.1016/j.calphad.2007.12.005) | Table 2, p. 6, row 42; `ORC-5NXXAZCV3G.f997db` | | | -45.9 kJ/mol-atom | VSi2 | | model | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [2] Broz 2013; _cites Zhang 2007_ [doi](https://doi.org/10.1007/s10853-007-1865-6) | Table 2, p. 6, row 41; `ORC-JRV4VLE5B5.f68ba6` | | | -29 kJ/mol-atom | VSi2 | | model | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [2] Broz 2013; _cites Chen 2006_ [doi](https://doi.org/10.1016/j.calphad.2006.04.004) | Table 2, p. 6, row 40; `ORC-4Y3CJJQB5F.d39aab` | | | -29 kJ/mol-atom | VSi2 | 298.15 | model | Miedema model | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [1] Zhang 2008; _cites Chen 2006_ [doi](https://doi.org/10.1016/j.calphad.2006.04.004) | Table 2, p. 3, row 15; `ORC-JJ45LQ5ECG` | | | -8.285 kJ/mol-atom | Si2V | | model | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [3] Luo 2018 | Table 3, p. 5, row 25; `ORC-S42MPJBDNY` | | | -47 kJ/mol-atom | Si2V | 0 | DFT | DFT | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [3] Luo 2018; _cites Broz 2013_ [doi](https://doi.org/10.1016/j.jssc.2012.12.003) | Table 3, p. 5, row 22; `ORC-2RO2CPZLGD` | | | -45.91 kJ/mol-atom | VSi2 | 298.15 | DFT | First-principles | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [1] Zhang 2008; _cites Zhang 2007_ [doi](https://doi.org/10.1007/s10853-007-1865-6) | Table 2, p. 3, row 19; `ORC-WQDQE3WMWA` | | | -47 kJ/mol-atom | VSi2 | 0 | unspecified | | [Si–V](https://data.orchid-project.org/systems/SI-V.html) | [2] Broz 2013 | Table 2, p. 6, row 35; `ORC-PR2BW2XU6M.8ea770` | | ### 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 Si2V | Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | 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. Table: 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](https://doi.org/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](https://doi.org/10.1007/s11837-013-0755-4) (CC BY 4.0); ## Sources 1. 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](https://doi.org/10.1016/j.calphad.2007.12.005) 2. 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](https://doi.org/10.1016/j.jssc.2012.12.003) 3. 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](https://doi.org/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). 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/).