Welcome to mendeleev’s documentation¶

Pythonic periodic table of elements

A Python package with a convenient API for accessing various properties of elements, ions, and isotopes in the periodic table. Visualize trends, explore chemical data, and integrate periodic table information into your scientific workflows.

Why mendeleev?¶

🎯 For Researchers & Scientists: Access peer-reviewed elemental data programmatically in your computational chemistry, materials science, or data science workflows. No more manual lookups or spreadsheet wrangling.
💡 For Educators & Students: Explore periodic trends interactively, create custom visualizations, and integrate chemical data into Jupyter notebooks for teaching and learning.
⚙️ For Developers: Simple, well-documented API with pandas integration. SQLAlchemy models for advanced queries. Type hints and unit support for production-ready code.
🔬 Trusted Data Sources: All data comes from peer-reviewed scientific literature with proper citations. See our bibliography for complete references.

Quick Start¶

See the Quick Start guide for copy-paste examples, or Installation for installation options.

from mendeleev import element

si = element("Si")
print(si.name)           # Silicon
print(si.atomic_number)  # 14

Key Features¶

📊 Rich Dataset → Data: 100+ properties per element including atomic, physical, thermodynamic, and electronic data from peer-reviewed sources
🔬 Isotope Information → Data: Complete isotope data with abundances, masses, half-lives, decay modes, and nuclear properties
📏 Units Support → Working with Physical Units: Integration with pint for unit-aware calculations and conversions (v1.1.0+)
📈 Visualization → Tutorials: Create custom periodic tables with bokeh, plotly, and seaborn
🗄️ Data Access → Accessing data: Query the SQLite database directly, export to pandas DataFrames, or use SQLAlchemy ORM for advanced queries
⚡ Multiple Access Methods → API Overview: Access by symbol, name, atomic number, or perform bulk queries with filtering
🐍 Pythonic API → API Reference: Clean, intuitive interface with type hints, docstrings, and extensive examples
📚 Well Documented → Tutorials: Comprehensive documentation with interactive Jupyter notebook tutorials and API reference
🧪 Electronegativity Scales → Electronegativities: Calculate electronegativity using 14+ different scales (Pauling, Allred-Rochow, Mulliken, etc.)
🔓 Open Source → Contributing to mendeleev: MIT licensed, actively maintained, with contributions welcome