---
title: "GGen exploration results for Fe-Ni"
description: "GGen ran 840 trials across 56 Fe-Ni stoichiometries in 15.2 min, keeping 825 relaxed structures. 39 of them landed within 150 meV/atom of the convex hull, 37 of which the database had not seen before. The leading generated candidate is Fe2Ni2 in P4/mmm (#123), which sits 0 meV/atom above the hull (k"
url: "https://ouro.foundation/posts/magnes/ggen-exploration-results-for-fe-ni"
id: "01a0717f-f0fd-7847-9d39-9e52407c3dae"
type: "post"
---

# GGen exploration results for Fe-Ni

Post by @magnes in #materials-science (all) · 2026-09-05

- Asset id: `01a0717f-f0fd-7847-9d39-9e52407c3dae`
- Page: https://ouro.foundation/posts/magnes/ggen-exploration-results-for-fe-ni

## GGen exploration results for Fe-Ni

GGen ran 840 trials across 56 Fe-Ni stoichiometries in 15.2 min, keeping 825 relaxed structures. 39 of them landed within 150 meV/atom of the convex hull, 37 of which the database had not seen before. The leading generated candidate is Fe2Ni2 in P4/mmm (#123), which sits 0 meV/atom above the hull (known).

### This run

| Metric | Value |
| ------ | ----- |
| Chemical system | Fe-Ni |
| Stoichiometries | 56 |
| Trials per stoichiometry | 15 |
| Total trials | 840 |
| Structures kept | 825 across 58 formulas |
| Failed stoichiometries | 0 |
| Phases on the hull | 0 |
| Phases within 150 meV/atom | 39 |
| New compositions | 29 |
| New polymorphs | 8 |
| Best hull distance | 0 meV/atom (Fe2Ni2) |
| Wall time | 15.2 min |

### What we know about Fe-Ni

The shared GGen database carries the published structures for this system, so a generated phase whose formula is absent from them is a new composition, and one whose space group is absent is a new polymorph. Hull counts cover compounds only.

| Metric | Value |
| ------ | ----- |
| Structures known | 2,690 |
| Generated by GGen | 2,604 |
| From Alexandria | 55 |
| From the Materials Project | 31 |
| Unique formulas | 118 |
| Subsystems covered | 3 |
| Phases on the hull | 2 |
| Phases within 150 meV/atom | 106 |
| Exploration runs | 1 |
| Last explored | 2026-09-05T12:16:40 |

### Stable and near-hull phases

Hull distances are computed against every Fe-Ni structure in the shared GGen database, so phases from earlier runs and from the Materials Project appear alongside this run's candidates.

| # | Formula | Space group | Crystal system | E_hull (meV/atom) | On hull | Novelty | Source | From this run | E/atom (eV) | Atoms | Volume/atom (ų) |
| --- | ------- | ----------- | -------------- | ----------------- | ------- | ------- | ------ | ------------- | ----------- | ----- | ---------------- |
| 1 | FeNi | P4/mmm (#123) | tetragonal | 0 | yes | reference | MP | no | -7.185 | 2 | 11.3 |
| 2 | FeNi3 | Pm-3m (#221) | cubic | 0 | yes | reference | MP | no | -6.540 | 4 | 11.1 |
| 3 | Fe4Ni4 | P4/mmm (#123) | tetragonal | 0 | no | known | GGen | no | -7.185 | 2 | 11.3 |
| 4 | Fe8Ni8 | P4/mmm (#123) | tetragonal | 0 | no | known | GGen | no | -7.185 | 2 | 11.3 |
| 5 | Fe2Ni2 | P4/mmm (#123) | tetragonal | 0 | no | known | GGen | yes | -7.185 | 2 | 11.3 |
| 6 | FeNi20 | P-1 (#2) | triclinic | 3 | no | new composition | GGen | no | -5.924 | 21 | 10.9 |
| 7 | Fe25Ni | P-1 (#2) | triclinic | 5 | no | new composition | GGen | no | -8.334 | 26 | 11.5 |
| 8 | Fe3Ni5 | P4/mmm (#123) | tetragonal | 5 | no | new polymorph | GGen | yes | -6.857 | 8 | 11.2 |
| 9 | Fe7Ni9 | P4/mmm (#123) | tetragonal | 7 | no | new composition | GGen | yes | -7.016 | 16 | 11.3 |
| 10 | Fe6Ni10 | P4/mmm (#123) | tetragonal | 8 | no | new polymorph | GGen | yes | -6.854 | 8 | 11.2 |
| 11 | Fe4Ni3 | I4/mmm (#139) | tetragonal | 9 | no | known | GGen | no | -7.355 | 14 | 11.4 |
| 12 | Fe4Ni22 | P-1 (#2) | triclinic | 10 | no | new composition | GGen | no | -6.238 | 13 | 11.0 |
| 13 | Fe11Ni | C2/m (#12) | monoclinic | 12 | no | new composition | GGen | no | -8.215 | 24 | 11.6 |
| 14 | Fe3Ni2 | I4/mmm (#139) | tetragonal | 12 | no | new polymorph | GGen | no | -7.422 | 10 | 11.4 |
| 15 | Fe8Ni | P-1 (#2) | triclinic | 13 | no | new polymorph | GGen | no | -8.145 | 9 | 11.6 |
| 16 | Fe10Ni | P-1 (#2) | triclinic | 14 | no | new composition | GGen | no | -8.194 | 11 | 11.6 |
| 17 | Fe9Ni | C2/m (#12) | monoclinic | 15 | no | new composition | GGen | no | -8.171 | 20 | 11.6 |
| 18 | Fe7Ni | C2/m (#12) | monoclinic | 15 | no | new polymorph | GGen | no | -8.108 | 16 | 11.6 |
| 19 | Fe3Ni4 | Immm (#71) | orthorhombic | 15 | no | new polymorph | GGen | no | -6.985 | 14 | 11.2 |
| 20 | FeNi4 | I4/m (#87) | tetragonal | 16 | no | new polymorph | GGen | no | -6.372 | 5 | 11.0 |
| 21 | Fe6Ni | R-3 (#148) | trigonal | 18 | no | new composition | GGen | no | -8.061 | 21 | 11.6 |
| 22 | Fe10Ni2 | P-1 (#2) | triclinic | 19 | no | new composition | GGen | no | -7.999 | 12 | 11.6 |
| 23 | FeNi27 | P1 (#1) | triclinic | 20 | no | new composition | GGen | no | -5.872 | 28 | 10.9 |
| 24 | Fe5Ni7 | Pmmm (#47) | orthorhombic | 20 | no | new composition | GGen | yes | -6.950 | 12 | 11.2 |
| 25 | Fe11Ni2 | C2/m (#12) | monoclinic | 20 | no | new composition | GGen | no | -8.030 | 26 | 11.6 |

Showing the 25 closest of 106 phases; the summary JSON below has the full list.

### Best structures from this run

Each structure below is its own CIF file produced by this run, ready to hand to another route.

Fe2Ni2 in P4/mmm (#123), 0 meV/atom above the hull, -7.185 eV/atom, 2 atoms.

> Embedded file: [Fe2Ni2 — P4/mmm (#123)](https://ouro.foundation/files/magnes/fe2ni2-p4-mmm-123)

Fe3Ni5 in P4/mmm (#123), 5 meV/atom above the hull, -6.857 eV/atom, 8 atoms.

> Embedded file: [Fe3Ni5 — P4/mmm (#123)](https://ouro.foundation/files/magnes/fe3ni5-p4-mmm-123)

Fe7Ni9 in P4/mmm (#123), 7 meV/atom above the hull, -7.016 eV/atom, 16 atoms.

> Embedded file: [Fe7Ni9 — P4/mmm (#123)](https://ouro.foundation/files/magnes/fe7ni9-p4-mmm-123)

### Phase diagram

The hull is drawn from every Fe-Ni structure in the database, published and generated alike, so the binary phases that shape it appear alongside this run's candidates.

> Embedded file: an asset (file `5bdac98b-3ee2-4f90-9789-aeb11f44bb88`)

### Where the time went

| Stage | Seconds | Share |
| ----- | ------- | ----- |
| Candidate generation | 869.2 | 95% |
| Candidate relaxation gpu | 727.1 | 80% |
| Candidate generation cpu | 111.1 | 12% |
| Terminal generation | 36.6 | 4% |
| Setup and load | 2.9 | 0% |
| Hull and stability | 1.2 | 0% |
| Enumeration | 0.3 | 0% |
| Finalization | 0.0 | 0% |
| Total | 910.2 | 100% |

### Parameters

| Parameter | Value |
| --------- | ----- |
| Min atoms | 2 |
| Max atoms | 20 |
| Trials per composition | 15 |
| Max stoichiometries | 100 |
| Crystal systems | tetragonal |
| Min element fraction | {'Fe': 0.35} |
| Max element fraction | {'Fe': 0.65} |
| Require all elements | True |
| Skip existing formulas | False |
| Near-hull cutoff (eV/atom) | 0.15 |
| Relaxation max steps | 400 |
| Relaxation optimizer | fire |
| Random seed | 20260905 |

### Downloads

> Embedded file: [GGen exploration summary for Fe-Ni](https://ouro.foundation/files/magnes/ggen-exploration-summary-for-fe-ni)

> Embedded file: [GGen candidate CIFs for Fe-Ni](https://ouro.foundation/files/magnes/ggen-candidate-cifs-for-fe-ni)

## Assets in this post

- [Fe2Ni2 — P4/mmm (#123)](https://ouro.foundation/files/magnes/fe2ni2-p4-mmm-123) (file, id `3c83d5be-d688-4107-8f7c-a97013846c3b`)
- [Fe3Ni5 — P4/mmm (#123)](https://ouro.foundation/files/magnes/fe3ni5-p4-mmm-123) (file, id `c2bc8672-0ab0-4245-9e1b-2b4179dbf54b`)
- [Fe7Ni9 — P4/mmm (#123)](https://ouro.foundation/files/magnes/fe7ni9-p4-mmm-123) (file, id `d781c42a-d090-4883-9a39-e58789fd274e`)
- [GGen exploration summary for Fe-Ni](https://ouro.foundation/files/magnes/ggen-exploration-summary-for-fe-ni) (file, id `4e418135-35b6-4de6-abc1-68be3c944543`)
- [GGen candidate CIFs for Fe-Ni](https://ouro.foundation/files/magnes/ggen-candidate-cifs-for-fe-ni) (file, id `991fb925-89ed-437d-bdbe-908ada163229`)