> For the complete documentation index, see [llms.txt](https://doc.duaer.com/zh/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/zh/getting-started/matpedia-2d.md).

# 在 Duaer 里查2DMatpedia 二维材料

在 Duaer 里：按化学式或元素检索 2DMatpedia 中计算得到的二维材料，含带隙与化学体系。一次成功查询用 1 额度。
## 能拿到什么

Duaer 数据市场里的「2DMatpedia 二维材料」：按化学式或元素检索 2DMatpedia 中计算得到的二维材料，含带隙与化学体系。查到结果时用 1 额度，结果交给数字组织的下一个节点。

从节点创建器选 Duaer 数据 → 2DMatpedia 二维材料，或打开 [数据市场](/zh/getting-started/data-market.md)。相关：[Materials Cloud MC3D](/zh/getting-started/materials-cloud.md)、[JARVIS-DFT](/zh/getting-started/jarvis.md)。

## 适合做什么

- 筛选单层二维材料及其带隙。
- 查找某层状晶体能否剥离成二维材料。

## 在画布里检索

1. 打开节点创建器，选 Duaer 数据 → 2DMatpedia。
2. 填 Formula（如 MoS2）或 Elements（如 Mo,S）。
3. Limit 默认 10，最大 20。执行。

查到结果才扣 1 额度；没有结果、输入有误或上游失败都不扣。

## 用 API 调用

- GET https://api.duaer.com/v1/data/matpedia-2d?formula=MoS2
- Authorization: Bearer <Duaer key>

下方是与数据市场「复制技能」相同的英文技能，含参数、示例与返回字段。

## 调用技能（英文）

与数据市场「复制技能」一致。

```
---
name: duaer-matpedia-2d
description: >-
  Duaer 2DMatpedia. Computed two-dimensional materials in 2DMatpedia by formula or elements, with band gap and chemical system.
  One successful search uses 1 Duaer credit.
---

# Duaer 2DMatpedia

Duaer 2DMatpedia searches an open database of single-layer (2D) materials obtained by exfoliating layered bulk crystals and by substitution, with DFT band gaps.

## When to use

- Find monolayer candidates such as MoS2 or graphene analogues.
- Screen 2D materials by band gap for electronics.

## When not to use

- Bulk 3D crystals. Use https://skills.duaer.com/materials-project.md.
- Experimental structures. Use https://skills.duaer.com/cod.md.

## Call

`GET https://api.duaer.com/v1/data/matpedia-2d?formula=MoS2`

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 MoS2. Matches the reduced formula.
- `elements` — Optional. Materials that contain all of these, such as Mo,S.
- `limit` — Optional. Rows to return, from 1 to 20. Default 10.

## Examples

- `GET https://api.duaer.com/v1/data/matpedia-2d?formula=MoS2` — MoS2 monolayers with band gaps.
- `GET https://api.duaer.com/v1/data/matpedia-2d?elements=W,Se&limit=5` — tungsten selenide layers.

## Result

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

- `structureId` — provider id.
- `formula`, `formulaCell`, `elements`, `sites` — reduced formula, cell formula, elements, and atoms in the cell.
- `bandGapEv` — DFT band gap in eV.
- `chemicalSystem` — elements joined by dashes, such as Mo-S.

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/materials-cloud.md — Duaer Materials Cloud MC3D
- https://skills.duaer.com/jarvis.md — Duaer JARVIS-DFT

```
## Questions

### Duaer 的2DMatpedia 二维材料检索扣多少额度？

查到结果时扣 1 额度；没有结果或出错不扣。

### Duaer 2DMatpedia 只有二维材料吗？

是。Duaer 2DMatpedia 只收录单层二维材料，来自层状体材料剥离与元素替换。

## 相关

- [在 Duaer 里查Materials Cloud MC3D](https://doc.duaer.com/zh/getting-started/materials-cloud.md)
- [在 Duaer 里查 JARVIS-DFT](https://doc.duaer.com/zh/getting-started/jarvis.md)