Materials Databases

Expert assistant for accessing materials science databases (AFLOW and Materials Project) to query crystal structures, materials properties, thermodynamic data, and computational results.

What This Skill Does

This skill enables Claude to help you:

• Access two major computational materials databases (Materials Project and AFLOW)
• Query crystal structures and download them in various formats
• Search for materials by composition, properties, or stability
• Retrieve electronic structure data (band gaps, DOS, band structures)
• Get thermodynamic properties (formation energies, phase stability)
• Access elastic, phonon, and surface properties
• Perform large-scale materials screening

When to Use This Skill

Use this skill when you need to:

• Find existing computational data for a material
• Screen materials databases for candidates with specific properties
• Compare experimental and computational structures
• Get band gaps, formation energies, or other calculated properties
• Build datasets for machine learning from databases
• Cross-reference data between different databases
• Download crystal structures for further calculations

Databases Covered

Materials Project (MP)

• Size: 150,000+ inorganic compounds
• Data: Electronic structure, phonons, elasticity, surfaces, batteries, molecules
• Access: Python API (mp-api) with rich query capabilities
• Requires: Free API key
• Best for: Detailed electronic/phonon data, phase diagrams, pymatgen integration

AFLOW (Automatic Flow)

• Size: 3.5+ million calculated materials
• Data: Structures, thermodynamics, elastic properties, ICSD references
• Access: REST API (no package required)
• Requires: No API key
• Best for: Large-scale screening, elastic properties, simple queries

Quick Start

1. Install Required Packages

# Materials Project API client
pip install mp-api

# Structure manipulation (recommended)
pip install pymatgen ase

# AFLOW (optional - can use requests instead)
pip install aflow requests

2. Get Materials Project API Key

1. Visit: https://materialsproject.org/api
2. Click "Generate API Key" (login with ORCID or email)
3. Copy your API key

3. Set Up Authentication

Option A: Environment variable (recommended)

export MP_API_KEY="your_api_key_here"

Option B: Configuration file

echo '{"MAPI_KEY": "your_api_key_here"}' > ~/.config/.mpapi.json

4. Test Your Setup

from mp_api.client import MPRester

# This should work without errors
with MPRester() as mpr:
    structure = mpr.get_structure_by_material_id("mp-149")
    print(f"Got structure: {structure.formula}")

Example Usage

Find Band Gap of Silicon

from mp_api.client import MPRester

with MPRester() as mpr:
    docs = mpr.materials.summary.search(
        formula="Si",
        fields=["material_id", "formula_pretty", "band_gap"]
    )
    for doc in docs:
        print(f"{doc.material_id}: {doc.formula_pretty}, Egap = {doc.band_gap} eV")

Screen for Stable Semiconductors

with MPRester() as mpr:
    docs = mpr.materials.summary.search(
        elements=["Ga", "N"],
        energy_above_hull=(0, 0.05),  # Thermodynamically stable
        band_gap=(1.0, 4.0),  # Semiconducting range
        fields=["material_id", "formula_pretty", "band_gap", "energy_above_hull"]
    )

Get Structure from AFLOW

import requests

# Get POSCAR file for FCC Silver
url = "http://aflowlib.duke.edu/AFLOWDATA/ICSD_WEB/FCC/Ag1/?geometry"
poscar = requests.get(url).text
print(poscar)

Files in This Skill

• SKILL.md - Complete skill instructions for Claude
• README.md - This file (overview and setup)
• QUICK_REFERENCE.md - Quick syntax reference
• references/materials-project.md - Detailed Materials Project API documentation
• references/aflow.md - AFLOW REST API and AFLUX query syntax
• examples/mp_search_examples.py - Materials Project query examples
• examples/aflow_search_examples.py - AFLOW query examples
• examples/structure_download.py - Download and save structures
• examples/property_screening.py - Multi-property screening workflow

Common Use Cases

1. Literature Support: "Find the band gap of GaN from Materials Project"
2. Structure Retrieval: "Download the crystal structure of rutile TiO2"
3. Materials Screening: "Find all stable ternary oxides with band gaps between 2-3 eV"
4. Data Collection: "Get formation energies for all binary transition metal oxides"
5. Cross-Database: "Compare elastic constants between AFLOW and Materials Project"
6. Phase Stability: "Check if Li2MnO3 is thermodynamically stable"

Tips

• Always specify fields in Materials Project queries to get only what you need
• Use AFLOW for quick lookups without API authentication
• Materials Project has better Python integration and documentation
• AFLOW has more entries but Materials Project has richer property data
• Combine both databases for comprehensive literature reviews
• Cache results locally to avoid repeated API calls

Resources

• Materials Project: https://materialsproject.org

  • API Docs: https://materialsproject.org/api
  • Python Client: https://github.com/materialsproject/api

• AFLOW: https://aflow.org

  • Documentation: https://aflow.org/documentation/
  • REST API: http://aflowlib.duke.edu

• Pymatgen: https://pymatgen.org (structure analysis toolkit)

Troubleshooting

"MPRestError: Unauthorized"

• Check that your API key is set correctly
• Verify the key at https://materialsproject.org/api

AFLOW queries timing out

• Try more specific search criteria
• AFLOW database is very large - narrow your search

No results found

• Check formula spelling (case-sensitive in some APIs)
• Try broader search criteria
• Some properties may not be available for all materials

Import errors

• Ensure mp-api is installed: pip install mp-api
• Update to latest version: pip install --upgrade mp-api

Version Information

• Skill created for mp-api v0.41+ (2024)
• Compatible with Materials Project next-gen API
• AFLOW REST API (current as of 2024)
• Pymatgen 2023.x and later recommended