# Materials Project

> Use when querying the Materials Project database for crystal structures, material properties, or generating phase diagrams. Requires the MP_API_KEY environment variable to be set.

- **Type:** Skill
- **Install:** `agentstack add skill-wugroup-xjtlu-cc-skills-zhenghaowu-group-materials-project`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [WuGroup-XJTLU](https://agentstack.voostack.com/s/wugroup-xjtlu)
- **Installs:** 0
- **Category:** [Databases](https://agentstack.voostack.com/c/databases)
- **Latest version:** 0.1.0
- **License:** Apache-2.0
- **Upstream author:** [WuGroup-XJTLU](https://github.com/WuGroup-XJTLU)
- **Source:** https://github.com/WuGroup-XJTLU/cc-skills-ZhenghaoWu-Group/tree/main/plugins/materials-project/skills/materials-project

## Install

```sh
agentstack add skill-wugroup-xjtlu-cc-skills-zhenghaowu-group-materials-project
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Materials Project API Skill

## Overview

Query the Materials Project database for structures, properties, and thermodynamic data.

## When to Use Materials Project vs. Other Tools

| Scenario | Recommended Tool | Why |
|---|---|---|
| Retrieving known crystal structures, band gaps, or phase diagrams from a curated database | **Materials Project API** | Fast access to DFT-computed data without running calculations |
| Exploring structures when no API key is available | **AFLOW / OQMD web interface** | Alternative open databases with overlapping coverage |
| Running custom DFT on a modified structure | **ASE + VASP / CP2K / PySCF** | Materials Project gives starting points, not bespoke calculations |

**Key rule:** Use the Materials Project API when you need experimentally or computationally validated structures and properties without running fresh quantum chemistry calculations.

## Setup

```bash
export MP_API_KEY="your_key_here"
```

## Core Capabilities

### 1. Query by Formula or Material ID

```bash
python scripts/query_materials.py --formula Fe2O3
python scripts/query_materials.py --material-id mp-149
```

### 2. Phase Diagrams

Generate phase diagrams for a chemical system.

```bash
python scripts/query_materials.py --chemsys Li-Fe-O --phase-diagram
```

## Output

Results are printed as JSON to stdout. Structures can be saved as CIF files with `--save-cif `.

## Anti-Patterns (Do Not Do These)

- **Do not query Materials Project without setting `MP_API_KEY`.** All requests will fail immediately with an authentication error.
- **Do not assume a formula query returns only one structure.** One formula can map to many polymorphs and oxidation states.
- **Do not use `energy_above_hull == 0` alone to guarantee synthesizability.** It indicates thermodynamic stability in the DFT phase diagram, not kinetic accessibility.
- **Do not neglect licensing and attribution.** Materials Project data should be cited appropriately in publications.

## Best Practices

- Batch queries when possible to reduce API round-trips.
- Filter by `energy_above_hull` to find stable phases; values closer to zero are more thermodynamically stable.
- Save structures as CIF with `--save-cif` if you plan to feed them into ASE, VASP, or visualization tools.
- When comparing computed properties across material families, be consistent about the functional and approximations used by the database version you are querying.
- **For questions about the latest Materials Project API features, newly added data fields, or version-specific syntax changes, use `WebFetch` on https://docs.materialsproject.org/ before answering.**

## Common Errors and Fixes

| Error / Symptom | Likely Cause | Fix |
|---|---|---|
| `MP_API_KEY environment variable not set` | Missing API key | Export `MP_API_KEY` before running the script |
| Connection error or timeout | Network issue or API rate limiting | Retry after a short delay or check Materials Project status page |
| Empty results for a formula | No matching entries in the database | Try a different formula formatting or search by element chemsys |
| `ValueError` during phase diagram generation | Entry mismatch or unsupported chemsys | Verify the chemsys string uses valid elements separated by hyphens |
| Missing properties in response | Data field not available for that material | Check the Materials Project documentation for field availability by version |

## References

- **Official Documentation**: https://docs.materialsproject.org/
- **MPRester API Reference**: https://docs.materialsproject.org/downloading-data/using-the-api/reference/
- **GitHub (pymatgen)**: https://github.com/materialsproject/pymatgen
- **GitHub (mp-api)**: https://github.com/materialsproject/api

## Getting Live Information

If the user asks about recently added features, new data fields, or version-specific syntax changes, use `WebFetch` on the official documentation at https://docs.materialsproject.org/ before answering.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [WuGroup-XJTLU](https://github.com/WuGroup-XJTLU)
- **Source:** [WuGroup-XJTLU/cc-skills-ZhenghaoWu-Group](https://github.com/WuGroup-XJTLU/cc-skills-ZhenghaoWu-Group)
- **License:** Apache-2.0

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-wugroup-xjtlu-cc-skills-zhenghaowu-group-materials-project
- Seller: https://agentstack.voostack.com/s/wugroup-xjtlu
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.