# Mo–N phases > Mo–N system: 8 phases (tier A 2, tier C 1, liquid 1, gas 1, needs_review 2, interstitial_fcc_a1_compound 1); 6 stable in a calculated diagram in the ORCHID phase registry, with names, structure type when the stored evidence supports an assignment under the stated tier rules, calculated stability, verbatim TDB PHASE/CONSTITUENT statements and example references. HTML: https://data.orchid-project.org/phases/pages/MO-N.html · Markdown: https://data.orchid-project.org/phases/pages/MO-N.md 8 phases (tier A 2, tier C 1, liquid 1, gas 1, needs_review 2, interstitial_fcc_a1_compound 1); 6 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model). Data: [interactive registry](https://orchid-project.org/phases/?q=MO-N) · [full JSON](https://data.orchid-project.org/phases/systems/MO-N.json) · [Mo–N system page](https://data.orchid-project.org/systems/MO-N.html) · [Markdown](https://data.orchid-project.org/phases/pages/MO-N.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md) Table: Phases of the Mo–N system (8) | Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models | |---|---|---|---|---:|---:| | [BCC_A2](#phase-mo-n-bcc-a2); _phase:mo-n:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–3999.14 K, x(N) 0–0.0019 | 1 | 2 | | [FCC_A1](#phase-mo-n-fcc-a1); _phase:mo-n:fcc-a1_ | NaCl · B1 · cF8 · Fm-3m (225) | assigned | stable in 1 of 2 calculated diagram(s): 300–1092.37 K, x(N) 0.30895–0.48355 | 2 | 2 | | [HCP_A3](#phase-mo-n-hcp-a3); _phase:mo-n:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | not stable in 2 calculated diagram(s) | 0 | 2 | | [LIQUID](#phase-mo-n-liquid); _phase:mo-n:liquid_ | liquid | liquid | stable in 2 of 2 calculated diagram(s): 2877.89–4000 K, x(N) 0–0.0096 | 1 | 2 | | [MC_SHP](#phase-mo-n-mc-shp); _phase:mo-n:mc-shp_ | WC · B_h · hP2 · P-6m2 (187) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–769.48 K, x(N) 0.5–0.5 | 0 | 1 | | [MO2N_B1](#phase-mo-n-mo2n-b1); _phase:mo-n:mo2n-b1_ | | needs_review | not stable in 1 calculated diagram(s) | 0 | 1 | | [MO2N_BETA](#phase-mo-n-mo2n-beta); _phase:mo-n:mo2n-beta_ | | needs_review | stable in 1 of 1 calculated diagram(s): 300–941.97 K, x(N) 0.28199–0.3332 | 0 | 1 | | [N2GAS](#phase-mo-n-n2gas); _phase:mo-n:n2gas_ | gas | gas | stable in 2 of 2 calculated diagram(s): 300–4000 K, x(N) 1–1 | 0 | 2 | ## BCC_A2 (Mo–N) - Id: `phase:mo-n:bcc-a2`; status `assigned` - Structure: W · A2 · cI2 · Im-3m (229); type `st:a2-w-ci2`; tier A: standard phase name; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 300–3999.14 K, x(N) 0–0.0019 - Literature: 1 values (1 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:mo-n:bcc-a2) Names (4): _corpus: _corpus:phase:mo-n:bcc-a2 _paper: _paper:10.2298/jmmb210330011d:BCC_A2 _tdb: _tdb:MoN-23Dac.tdb:BCC_A2, tdb:MoN-91Fri-LB.tdb:BCC_A2 ### TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written [MoN-23Dac.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-23Dac.tdb): BCC_A2, type code %B, sha256 `d0327d2feb226fde…` ~~~~text 48: PHASE BCC_A2 %B 2 1 3 ! 49: CONST BCC_A2 : MO : N VA% : ! ~~~~ [MoN-91Fri-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-91Fri-LB.tdb): BCC_A2, type code %B, sha256 `1d4dea1aad84fb4b…` ~~~~text 34: PHASE BCC_A2 %B 2 1 3 ! 35: CONST BCC_A2 : MO : N VA% : ! ~~~~ Example references (3 of 3; assessments first): - [doi:10.2298/JMMB210330011D](https://doi.org/10.2298/JMMB210330011D) R.A. Daclan, M.G. Mena, M.R. Vazquez, W. Gierlotka, J. Mining Metall. B, 59, 125-36(2023). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0364-5916(91)90028-I](https://doi.org/10.1016/0364-5916%2891%2990028-I) K. Frisk, Calphad, 15, 79-106(1991). _assessment that models this phase_ - [doi:10.1016/0022-5088(78)90073-5](https://doi.org/10.1016/0022-5088%2878%2990073-5) Hermann Jehn, Peter Ettmayer, The molybdenum-nitrogen phase diagram, Journal of the Less Common Metals 58, 85-98 (1978). _cited as the source of values for this phase_ ## FCC_A1 (Mo–N) - Id: `phase:mo-n:fcc-a1`; status `assigned` - Structure: NaCl · B1 · cF8 · Fm-3m (225); type `st:b1-nacl-cf8`; interstitial_fcc_a1_compound; confidence high - Stability: stable in 1 of 2 calculated diagram(s): 300–1092.37 K, x(N) 0.30895–0.48355 - Literature: 2 values (2 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:mo-n:fcc-a1) Names (4): _corpus: _corpus:phase:mo-n:fcc-a1 _paper: _paper:10.1016/0364-5916(91)90028-i:MoN _tdb: _tdb:MoN-23Dac.tdb:FCC_A1, tdb:MoN-91Fri-LB.tdb:FCC_A1 ### TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written [MoN-23Dac.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-23Dac.tdb): FCC_A1, type code %A, sha256 `d0327d2feb226fde…` ~~~~text 43: PHASE FCC_A1 %A 2 1 1 ! 44: CONST FCC_A1 : MO : N VA% : ! ~~~~ [MoN-91Fri-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-91Fri-LB.tdb): FCC_A1, type code %A, sha256 `1d4dea1aad84fb4b…` ~~~~text 29: PHASE FCC_A1 %A 2 1 1 ! 30: CONST FCC_A1 : MO : N VA% : ! ~~~~ Example references (2 of 2; assessments first): - [doi:10.1016/0364-5916(91)90028-I](https://doi.org/10.1016/0364-5916%2891%2990028-I) K. Frisk, Calphad, 15, 79-106(1991). _assessment that models this phase; reports values for this phase_ - [doi:10.2298/JMMB210330011D](https://doi.org/10.2298/JMMB210330011D) R.A. Daclan, M.G. Mena, M.R. Vazquez, W. Gierlotka, J. Mining Metall. B, 59, 125-36(2023). _assessment that models this phase_ ## HCP_A3 (Mo–N) - Id: `phase:mo-n:hcp-a3`; status `assigned` - Structure: Mg · A3 · hP2 · P6_3/mmc (194); type `st:a3-mg-hp2`; tier A: standard phase name; confidence high - Stability: not stable in 2 calculated diagram(s) - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:mo-n:hcp-a3) Names (3): _corpus: _corpus:phase:mo-n:hcp-a3 _tdb: _tdb:MoN-23Dac.tdb:HCP_A3, tdb:MoN-91Fri-LB.tdb:HCP_A3 ### TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written [MoN-23Dac.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-23Dac.tdb): HCP_A3, type code %, sha256 `d0327d2feb226fde…` ~~~~text 53: PHASE HCP_A3 % 2 1 0.5 ! 54: CONST HCP_A3 : MO : N VA% : ! ~~~~ [MoN-91Fri-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-91Fri-LB.tdb): HCP_A3, type code %, sha256 `1d4dea1aad84fb4b…` ~~~~text 39: PHASE HCP_A3 % 2 1 0.5 ! 40: CONST HCP_A3 : MO : N VA% : ! ~~~~ Example references (2 of 2; assessments first): - [doi:10.1016/0364-5916(91)90028-I](https://doi.org/10.1016/0364-5916%2891%2990028-I) K. Frisk, Calphad, 15, 79-106(1991). _assessment that models this phase_ - [doi:10.2298/JMMB210330011D](https://doi.org/10.2298/JMMB210330011D) R.A. Daclan, M.G. Mena, M.R. Vazquez, W. Gierlotka, J. Mining Metall. B, 59, 125-36(2023). _assessment that models this phase_ ## LIQUID (Mo–N) - Id: `phase:mo-n:liquid`; status `assigned` - Structure: liquid; type `st:liquid`; liquid; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 2877.89–4000 K, x(N) 0–0.0096 - Literature: 1 values (1 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:mo-n:liquid) Names (4): _corpus: _corpus:phase:mo-n:liquid _paper: _paper:10.2298/jmmb210330011d:Liquid _tdb: _tdb:MoN-23Dac.tdb:LIQUID, tdb:MoN-91Fri-LB.tdb:LIQUID ### TDB models of LIQUID (2): PHASE and CONSTITUENT statements as written [MoN-23Dac.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-23Dac.tdb): LIQUID, type code %, sha256 `d0327d2feb226fde…` ~~~~text 38: PHASE LIQUID:L % 1 1 ! 39: CONST LIQUID:L : MO N : ! ~~~~ [MoN-91Fri-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-91Fri-LB.tdb): LIQUID, type code %, sha256 `1d4dea1aad84fb4b…` ~~~~text 24: PHASE LIQUID:L % 1 1 ! 25: CONST LIQUID:L : MO N : ! ~~~~ Example references (3 of 3; assessments first): - [doi:10.2298/JMMB210330011D](https://doi.org/10.2298/JMMB210330011D) R.A. Daclan, M.G. Mena, M.R. Vazquez, W. Gierlotka, J. Mining Metall. B, 59, 125-36(2023). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0364-5916(91)90028-I](https://doi.org/10.1016/0364-5916%2891%2990028-I) K. Frisk, Calphad, 15, 79-106(1991). _assessment that models this phase_ - [doi:10.1016/0022-5088(78)90073-5](https://doi.org/10.1016/0022-5088%2878%2990073-5) Hermann Jehn, Peter Ettmayer, The molybdenum-nitrogen phase diagram, Journal of the Less Common Metals 58, 85-98 (1978). _cited as the source of values for this phase_ ## MC_SHP (Mo–N) - Id: `phase:mo-n:mc-shp`; status `assigned` - Structure: WC · B_h · hP2 · P-6m2 (187); type `st:b-h-wc-hp2`; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated - Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) [doi:10.1016/j.calphad.2025.102833](https://doi.org/10.1016/j.calphad.2025.102833) - Caveat: not certain from the name or DFT alone (name_has_descriptive_tokens:MC,SHP, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system - Stoichiometry: Mo 0.5000, N 0.5000 - Stability: stable in 1 of 1 calculated diagram(s): 300–769.48 K, x(N) 0.5–0.5 - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:mo-n:mc-shp) Names (2): _corpus: _corpus:phase:mo-n:mc-shp _tdb: _tdb:MoN-23Dac.tdb:MC_SHP ### TDB models of MC_SHP (1): PHASE and CONSTITUENT statements as written [MoN-23Dac.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-23Dac.tdb): MC_SHP, type code %, sha256 `d0327d2feb226fde…` ~~~~text 69: PHASE MC_SHP % 2 1 1 ! 70: CONST MC_SHP : MO : N : ! ~~~~ Example references (1 of 1; assessments first): - [doi:10.2298/JMMB210330011D](https://doi.org/10.2298/JMMB210330011D) R.A. Daclan, M.G. Mena, M.R. Vazquez, W. Gierlotka, J. Mining Metall. B, 59, 125-36(2023). _assessment that models this phase_ ## MO2N_B1 (Mo–N) - Id: `phase:mo-n:mo2n-b1`; status `needs_review` - No structure assigned. Why: site_ratios_contradict_B1:MoN-23Dac.tdb - Candidate (name_token): NaCl · B1 · cF8 · Fm-3m (225) — Strukturbericht/word 'B1' in the TDB name - Candidate (sgte_mmc2): NaCl · B1 · cF8 · Fm-3m (225) — Hallstedt 2025 mmc2 row for MO2N_B1: Mo2N-gamma - Candidate (tdb_comment): NaCl · cF8 · Fm-3m — MoN-23Dac.tdb: 'Prototype NaCl (cF8, Fm-3m), gamma' - Stability: not stable in 1 calculated diagram(s) - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:mo-n:mo2n-b1) Names (2): _corpus: _corpus:phase:mo-n:mo2n-b1 _tdb: _tdb:MoN-23Dac.tdb:MO2N_B1 ### TDB models of MO2N_B1 (1): PHASE and CONSTITUENT statements as written [MoN-23Dac.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-23Dac.tdb): MO2N_B1, type code %, sha256 `d0327d2feb226fde…` ~~~~text 63: PHASE MO2N_B1 % 2 2 1 ! 64: CONST MO2N_B1 : MO : N% VA : ! ~~~~ Example references (1 of 1; assessments first): - [doi:10.2298/JMMB210330011D](https://doi.org/10.2298/JMMB210330011D) R.A. Daclan, M.G. Mena, M.R. Vazquez, W. Gierlotka, J. Mining Metall. B, 59, 125-36(2023). _assessment that models this phase_ ## MO2N_BETA (Mo–N) - Id: `phase:mo-n:mo2n-beta`; status `needs_review` - No structure assigned. Why: no_structure_token; off_stoichiometric_model - Candidate (sgte_mmc2): Mo2N · tI12 · I4_1/amd (141) — Hallstedt 2025 mmc2 row for MO2N_BETA: Mo2N-beta - Candidate (tdb_comment): Mo2N · tI12 · I4_1/amd, 141 — MoN-23Dac.tdb: 'Prototype Mo2N (tI12, I4_1/amd, 141)' - Stability: stable in 1 of 1 calculated diagram(s): 300–941.97 K, x(N) 0.28199–0.3332 - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:mo-n:mo2n-beta) Names (2): _corpus: _corpus:phase:mo-n:mo2n-beta _tdb: _tdb:MoN-23Dac.tdb:MO2N_BETA ### TDB models of MO2N_BETA (1): PHASE and CONSTITUENT statements as written [MoN-23Dac.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-23Dac.tdb): MO2N_BETA, type code %, sha256 `d0327d2feb226fde…` ~~~~text 58: PHASE MO2N_BETA % 2 2 1 ! 59: CONST MO2N_BETA : MO : N% VA : ! ~~~~ Example references (1 of 1; assessments first): - [doi:10.2298/JMMB210330011D](https://doi.org/10.2298/JMMB210330011D) R.A. Daclan, M.G. Mena, M.R. Vazquez, W. Gierlotka, J. Mining Metall. B, 59, 125-36(2023). _assessment that models this phase_ ## N2GAS (Mo–N) - Id: `phase:mo-n:n2gas`; status `assigned` - Structure: gas; type `st:gas`; gas; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 300–4000 K, x(N) 1–1 - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:mo-n:n2gas) Names (3): _corpus: _corpus:phase:mo-n:n2gas _tdb: _tdb:MoN-23Dac.tdb:N2GAS, tdb:MoN-91Fri-LB.tdb:N2GAS ### TDB models of N2GAS (2): PHASE and CONSTITUENT statements as written [MoN-23Dac.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-23Dac.tdb): N2GAS, type code %, sha256 `d0327d2feb226fde…` ~~~~text 72: PHASE N2GAS % 1 1 ! 73: CONST N2GAS : N2 : ! ~~~~ [MoN-91Fri-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/MoN-91Fri-LB.tdb): N2GAS, type code %, sha256 `1d4dea1aad84fb4b…` ~~~~text 42: PHASE N2GAS % 1 1 ! 43: CONST N2GAS : N2 : ! ~~~~ Example references (2 of 2; assessments first): - [doi:10.1016/0364-5916(91)90028-I](https://doi.org/10.1016/0364-5916%2891%2990028-I) K. Frisk, Calphad, 15, 79-106(1991). _assessment that models this phase_ - [doi:10.2298/JMMB210330011D](https://doi.org/10.2298/JMMB210330011D) R.A. Daclan, M.G. Mena, M.R. Vazquez, W. Gierlotka, J. Mining Metall. B, 59, 125-36(2023). _assessment that models this phase_ ## Please cite - R. Arróyave, J. Saal, D. Shin, ORCHID-Registry: phase registry of binary systems (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735970 - 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 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); the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work). 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_phase_registry_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID-Registry: phase registry of binary systems}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23735970}, url = {https://doi.org/10.5281/zenodo.23735970}, 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 the ORCHID phase registry and the sources named on the page (TDB assessments, Hallstedt 2025, Materials Project, OQMD). TDB statements are quoted as written; parameter expressions are not reproduced. Field reference: [SCHEMA.md](https://data.orchid-project.org/phases/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt).