> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/getting-started/aflow.md).

# AFLOW in Duaer

In Duaer: Computed materials from AFLOW by formula or elements: band gap, formation enthalpy, space group, and Pearson symbol. One successful search uses 1 credit.
## What you get

Duaer AFLOW searches the AFLOW database of high-throughput DFT calculations. A formula matches the reduced formula; elements find every compound containing them.

Pick Duaer Data → AFLOW in the node creator, or open the [data market](/getting-started/data-market.md). Related: [Alexandria](/getting-started/alexandria.md), [Materials Project](/getting-started/materials-project.md).

## When to use it

- Screen candidate compounds by band gap or formation enthalpy.
- Compare polymorphs of one formula.

## When not to use it

- Experimental structures. Use [Crystal structures (COD)](/getting-started/cod.md).
- Simulation runs and raw files. Use [NOMAD](/getting-started/nomad.md).

## Search on the canvas

1. Open the node creator and pick Duaer Data → AFLOW.
2. Fill Formula (such as TiO2) or Elements (such as Ti,O).
3. Limit defaults to 10, max 20. Execute.

A search uses 1 credit only when it returns rows. No rows, wrong input, or an upstream failure uses 0.

## Call the API

- GET https://api.duaer.com/v1/data/aflow?formula=TiO2
- Authorization: Bearer <Duaer key>

The call skill below matches Copy skill in the Duaer data market, with parameters, examples, and result fields.

## Call skill

Same text as Copy skill.

```
---
name: duaer-aflow
description: >-
  Duaer AFLOW. Computed materials from AFLOW by formula or elements: band gap, formation enthalpy, space group, and Pearson symbol.
  One successful search uses 1 Duaer credit.
---

# Duaer AFLOW

Duaer AFLOW searches the AFLOW database of high-throughput DFT calculations. A formula matches the reduced formula; elements find every compound containing them.

## When to use

- Screen candidate compounds by band gap or formation enthalpy.
- Compare polymorphs of one formula.

## When not to use

- Experimental structures. Use https://skills.duaer.com/cod.md.
- Simulation runs and raw files. Use https://skills.duaer.com/nomad.md.

## Call

`GET https://api.duaer.com/v1/data/aflow?formula=TiO2`

Header: `Authorization: Bearer <Duaer key>`

Use an account key or a model API key.

Get a Duaer key: https://skills.duaer.com/keys.md

## Parameters

Provide `formula` or `elements`.

- `formula` — Formula such as TiO2. Matches the reduced formula.
- `elements` — Optional. Materials that contain all of these, such as Ti,O.
- `limit` — Optional. Rows to return, from 1 to 20. Default 10.

## Examples

- `GET https://api.duaer.com/v1/data/aflow?formula=TiO2` — TiO2 polymorphs with band gaps.
- `GET https://api.duaer.com/v1/data/aflow?elements=Li,Fe&limit=5` — compounds containing lithium and iron.

## Result

The response is `{ "items": [...] }`. Each item has `source`, `title`, `url`, and `summary`, plus:

- `auid`, `aflowPath` — AFLOW ids.
- `formula`, `compound`, `elements` — reduced formula, cell formula, and elements.
- `spaceGroupNumber`, `pearsonSymbol` — relaxed symmetry.
- `bandGapEv`, `formationEnthalpyEvPerAtom` — electronic gap and stability.

AFLOW can take several seconds to answer.

Fields without a value are left out.

## Credits

A search that returns at least one row uses 1 credit.
An empty search, a search that finds nothing, or a failed search uses 0.
Wrong input returns 400 with a message and uses 0.
No remaining credits returns 402 and does not search.
A missing key returns 401.

## Related

- https://skills.duaer.com/alexandria.md — Duaer Alexandria
- https://skills.duaer.com/materials-project.md — Duaer Materials Project

```
## Questions

### How many credits does a AFLOW search use in Duaer?

One credit when Duaer returns rows. A search with no rows or an error uses 0.

### Why is Duaer AFLOW slower than other sources?

The AFLOW service often takes several seconds. Duaer then keeps only rows whose reduced formula matches.

## Related

- [Alexandria in Duaer](https://doc.duaer.com/getting-started/alexandria.md)
- [Materials Project in Duaer](https://doc.duaer.com/getting-started/materials-project.md)