⚛️ DFT Flight Simulator

Complete Interactive Learning Platform for Density Functional Theory

Explore the three pillars of DFT calculations: Basis Sets, Pseudopotentials, and XC Functionals through stunning visualizations and comprehensive comparisons.

🚀 Quick Start

1. Install Dependencies

pip install -r requirements.txt

2. Download Basis Set Cache (One-time, ~2-3 minutes)

python3 download_basis_cache.py

This downloads metadata for 500+ basis sets locally for fast access.

3. Run the App

New Multi-Page App (Recommended):

streamlit run app.py

Legacy Single-Page App:

streamlit run basis_visualizer_app.py

Open http://localhost:8501 in your browser.

✨ Features

📦 Module 1: Basis Sets

• 748 basis sets from basis-set-exchange
• 3D orbital visualization with interactive rotation
• Comparison mode for side-by-side analysis
• Shell analysis and zeta level determination
• Export to any software (Gaussian, ORCA, PySCF, etc.)

⚛️ Module 2: Pseudopotentials

• 432 pseudopotentials from PseudoDojo
• 3 functionals: PBE, LDA, PW
• 2 accuracies: Standard (soft) and Stringent (hard)
• Visual comparison of Coulomb vs Pseudopotential
• Core radius analysis and smoothing visualization

🔧 Module 3: XC Functionals

• 18+ functionals (LDA, GGA, Hybrid, meta-GGA)
• Jacob's Ladder visualization
• Enhancement factor plots for mathematical understanding
• Functional comparison with difference analysis
• Use case recommendations for each functional

🎯 Cross-Module Features

• Consistency checker – Ensures compatible selections
• Session state – Selections persist across modules
• Educational content – Learn as you explore
• Fast caching – Optimized performance

🎓 Learning Features

The app helps you understand:

• What is a basis set? Mathematical functions describing electron orbitals
• Single vs Double vs Triple-ζ: More functions = more accuracy but slower
• Polarization: d and f functions for better bonding description
• STO vs GTO: Slater vs Gaussian type orbitals
• Why some are expensive: More primitives = more calculations

🔄 Updating Cache

The cache shows its age in the sidebar. To update:

python3 download_basis_cache.py

Recommended: Update monthly to get new basis sets.

📁 Project Structure

DFT_TOOLS/
├── basis_visualizer_app.py      # Main application
├── download_basis_cache.py      # Cache downloader
├── basis_cache/                 # Local cache directory
│   └── metadata.json           # Cached basis set info
├── requirements.txt             # Python dependencies
└── README.md                    # This file

🐛 Troubleshooting

"Cache not found" error:

python3 download_basis_cache.py

App is slow:

• Make sure cache is downloaded
• Reduce grid points in visualization (edit line 177)

Element not available:

• Some basis sets don't support all elements
• Try a different basis set (e.g., STO-3G, 6-31G)

💡 Tips

1. Start with simple basis sets (STO-3G, 3-21G) to understand concepts
2. Use comparison mode to see differences between similar basis sets
3. Read the educational tooltips (? icons)
4. Export basis sets for your quantum chemistry calculations

🎯 Best Basis Sets to Start With

• STO-3G: Minimal, fast, educational
• 6-31G: Classic double-zeta
• 6-31G:* With polarization
• cc-pVDZ: Correlation-consistent double-zeta
• cc-pVTZ: Triple-zeta, more accurate

📊 Technical Details

• Built with Streamlit + Plotly
• Uses Basis Set Exchange (BSE) library
• 3D visualization with isosurfaces
• Gaussian-type orbital (GTO) rendering

🙏 Credits

• Basis Set Exchange: https://www.basissetexchange.org/
• Data from the MolSSI BSE project

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Made for learning quantum chemistry! 🧪✨