入门
在 Duaer 里查Materials Cloud MC3D
在 Duaer 里：按化学式或元素检索 Materials Cloud MC3D 中以 PBE 弛豫的三维晶体结构，含晶胞体积、总能与来源数据库。一次成功查询用 1 额度。
能拿到什么
Duaer 数据市场里的「Materials Cloud MC3D」：按化学式或元素检索 Materials Cloud MC3D 中以 PBE 弛豫的三维晶体结构，含晶胞体积、总能与来源数据库。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 → Materials Cloud MC3D，或打开 数据市场。相关：Materials Project、Alexandria。
适合做什么
- 查找实验已知晶体经 DFT 弛豫后的结构。
- 追溯某结构来自哪个实验数据库。
在画布里检索
- 打开节点创建器，选 Duaer 数据 → Materials Cloud MC3D。
- 填 Formula（如 SiO2）或 Elements（如 Si,O）。
- 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/materials-cloud?formula=SiO2
- 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-materials-cloud
description: >-
Duaer Materials Cloud MC3D. Relaxed 3D crystal structures computed with PBE in Materials Cloud MC3D, by formula or elements, with cell volume, energy, and source database.
One successful search uses 1 Duaer credit.
---
# Duaer Materials Cloud MC3D
Duaer Materials Cloud MC3D searches the MC3D database of experimentally known 3D crystals relaxed with DFT (PBE) by the Materials Cloud team. Each row names the experimental database the structure came from.
## When to use
- Get a DFT-relaxed version of a known experimental crystal.
- Compare cell volume and magnetization across polymorphs.
## When not to use
- Band gaps and hull stability. Use https://skills.duaer.com/materials-project.md.
- Raw experimental CIFs. Use https://skills.duaer.com/cod.md.
## Call
`GET https://api.duaer.com/v1/data/materials-cloud?formula=SiO2`
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 SiO2. Matches the reduced formula.
- `elements` — Optional. Materials that contain all of these, such as Si,O.
- `limit` — Optional. Rows to return, from 1 to 20. Default 10.
## Examples
- `GET https://api.duaer.com/v1/data/materials-cloud?formula=SiO2` — relaxed silica polymorphs.
- `GET https://api.duaer.com/v1/data/materials-cloud?elements=Li,Co,O&limit=5` — lithium cobalt oxides.
## 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.
- `mc3dId`, `sourceDatabase`, `sourceId` — MC3D id and the experimental source (such as mpds or cod).
- `totalEnergyEv`, `cellVolumeA3`, `totalMagnetization` — DFT energy, cell volume in ų, and magnetization.
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-project.md — Duaer Materials Project
- https://skills.duaer.com/alexandria.md — Duaer Alexandria
常见问题
Duaer 的Materials Cloud MC3D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 Materials Cloud MC3D 的结构从哪里来？
Duaer Materials Cloud MC3D 收录实验已知的三维晶体，用 DFT（PBE）弛豫；每行注明来源的实验数据库。
同组