# Hf–O–Si system > Hf–O–Si system: 7 accepted literature values (crystal structure 6, invariant reaction 1) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote. HTML: https://data.orchid-project.org/systems/HF-O-SI.html · Markdown: https://data.orchid-project.org/systems/HF-O-SI.md 7 accepted literature values from 1 paper(s) (experimental 1, DFT 6); 0 calculated phase diagram(s). Data: [JSON](https://data.orchid-project.org/literature/systems/HF-O-SI.json) · [CSV](https://data.orchid-project.org/systems/HF-O-SI.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#HF-O-SI) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/HF-O-SI.html) · [Markdown](https://data.orchid-project.org/systems/HF-O-SI.md) Table: Accepted values by evidence class | Evidence class | Values | |---|---:| | experimental | 1 | | DFT | 6 | Table: Accepted values by property group | Property group | Values | |---|---:| | invariant reaction | 1 | | crystal structure | 6 | ## Invariant reactions (literature) Table: Invariant reactions reported in the literature for the Hf–O–Si system (1) | T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote | |---:|---|---|---|---|---|---| | 2023 | peritectic: Liquid +HfO2 (Monoclinic) → HfSiO4 | | experimental | [1] Shin 2006 | p. 9; `ORC-W7UVUBDE5A` | “The enthalpy of formation of HfSiO4 is obtained from first-principles calculations and the entropy of formation is evaluated from its peritectic reaction, Liquid +HfO2 (Monoclinic) → HfSiO4 , at 2023 K as reported by” | ## Other properties ### Crystal structure (6) Table: Crystal structure, Hf–O–Si system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Lattice a | 3.198 Å | 0 | HCP_A3 (Hf); _alloy: O 0, Si 0_ | DFT | [1] Shin 2006 | Table 1, p. 3, row 1; `ORC-QFMHTQTNMY.cbd710` | | | Lattice a | 6.616 Å | 0 | HfSiO4; _alloy: O 0.666667, Si 0.166667_ | DFT | [1] Shin 2006 | Table 1, p. 3, row 8; `ORC-P4GZ6FIB26.ad9114` | | | Lattice b | 3.198 Å | 0 | HCP_A3 (Hf); _alloy: O 0, Si 0_ | DFT | [1] Shin 2006 | Table 1, p. 3, row 1; `ORC-QFMHTQTNMY.70631f` | | | Lattice b | 6.616 Å | 0 | HfSiO4; _alloy: O 0.666667, Si 0.166667_ | DFT | [1] Shin 2006 | Table 1, p. 3, row 8; `ORC-P4GZ6FIB26.94d2d8` | | | Lattice c | 5.053 Å | 0 | HCP_A3 (Hf); _alloy: O 0, Si 0_ | DFT | [1] Shin 2006 | Table 1, p. 3, row 1; `ORC-QFMHTQTNMY.1e3b90` | | | Lattice c | 6.004 Å | 0 | HfSiO4; _alloy: O 0.666667, Si 0.166667_ | DFT | [1] Shin 2006 | Table 1, p. 3, row 8; `ORC-P4GZ6FIB26.10b7d4` | | ## Sources Reporting papers the values were read from (a value cited from another work names that work in its row). 1. Dongwon Shin, Raymundo Arróyave, Zi-Kui Liu, Thermodynamic modeling of the Hf–Si–O system, Calphad 30, 375-386 (2006). [doi:10.1016/j.calphad.2006.08.006](https://doi.org/10.1016/j.calphad.2006.08.006) ## 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 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); 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; 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). 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_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/).