# Np system > Np system: 9 accepted literature values (crystal structure 9) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote. HTML: https://data.orchid-project.org/systems/NP.html · Markdown: https://data.orchid-project.org/systems/NP.md 9 accepted literature values from 2 paper(s) (unspecified 9); 0 calculated phase diagram(s). Data: [JSON](https://data.orchid-project.org/literature/systems/NP.json) · [CSV](https://data.orchid-project.org/systems/NP.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#NP) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/NP.html) · [Markdown](https://data.orchid-project.org/systems/NP.md) Table: Accepted values by evidence class | Evidence class | Values | |---|---:| | unspecified | 9 | Table: Accepted values by property group | Property group | Values | |---|---:| | crystal structure | 9 | ## Other properties ### Crystal structure (9) Table: Crystal structure, Np system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Lattice a | 6.663 Å | 293 | α-Np | unspecified | [1] Smith 2016; _cites Lemire 2001_ | Table 1, p. 2, row 1; `ORC-7OBOB3EITQ.ccb2b2` | | | Lattice a | 4.897 Å | 586 | β-Np | unspecified | [1] Smith 2016; _cites Lemire 2001_ | Table 1, p. 2, row 2; `ORC-4EN2VZ2N57.c89f55` | | | Lattice a | 3.518 Å | 873 | γ-Np | unspecified | [1] Smith 2016; _cites Lemire 2001_ | Table 1, p. 2, row 3; `ORC-VVFSK2FLSK` | | | Lattice b | 4.723 Å | 293 | α-Np | unspecified | [1] Smith 2016; _cites Lemire 2001_ | Table 1, p. 2, row 1; `ORC-7OBOB3EITQ.198982` | | | Lattice c | 4.887 Å | 293 | α-Np | unspecified | [1] Smith 2016; _cites Lemire 2001_ | Table 1, p. 2, row 1; `ORC-7OBOB3EITQ.e19306` | | | Lattice c | 3.388 Å | 586 | β-Np | unspecified | [1] Smith 2016; _cites Lemire 2001_ | Table 1, p. 2, row 2; `ORC-4EN2VZ2N57.786275` | | | Molar volume; _printed: V_ | 12.16 cm^3 mol^-1 | | B.c.c.; _alloy: Np 1_ | unspecified | [2] Ogawa 1993 | Table 1, p. 2, row 5; `ORC-DSLM6WAGJB` | | | Molar volume; _printed: V_ | 12.16 cm^3 mol^-1 | | F.c.c.; _alloy: Np 1_ | unspecified | [2] Ogawa 1993 | Table 1, p. 2, row 6; `ORC-2QIKQXT4WM` | | | Molar volume; _printed: V_ | 13.1 cm^3 mol^-1 | | Liquid; _alloy: Np 1_ | unspecified | [2] Ogawa 1993 | Table 1, p. 2, row 4; `ORC-GRHLEBOOAS` | | ## Sources Reporting papers the values were read from (a value cited from another work names that work in its row). 1. A.L. Smith, J.-Y. Colle, O. Beneš, R.J.M. Konings, B. Sundman, C. Guéneau, Thermodynamic assessment of the neptunium–oxygen system: Mass spectrometric studies and thermodynamic modelling, The Journal of Chemical Thermodynamics 103, 257-275 (2016). [doi:10.1016/j.jct.2016.07.040](https://doi.org/10.1016/j.jct.2016.07.040) 2. Toru Ogawa, Alloying behaviour among U, Np, Pu and Am predicted with the Brewer valence bond model, Journal of Alloys and Compounds 194, 1-7 (1993). [doi:10.1016/0925-8388(93)90636-2](https://doi.org/10.1016/0925-8388%2893%2990636-2) ## 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/).