What is q2m3?

q2m3 is a hybrid quantum-classical QM/MM framework for small-molecule quantum chemistry workflows that combine PySCF, PennyLane QPE circuits, explicit MM point charges, Monte Carlo solvation, and EFTQC resource estimation.

The documentation emphasizes lightweight H2 examples first. Catalyst, H3O+, 8-bit QPE, and dynamic-Trotter diagnostics are documented as optional paths because they can require substantially more memory and compile time.

User Guide

• Getting Started
  • Requirements
  • Installation
  • First Validation
  • Quick API Check
  • Runtime And Memory Tiers
  • Basic Solvation Run
  • Troubleshooting
  • Next Steps
• Core Concepts
  • QM/MM Partitioning
  • QPE Workflow
  • Active Spaces
  • Phase Decoding And Energy Shifts
  • RDM Measurement
  • Resource Estimation
  • Fixed-MO Full-One-Electron Embedding
  • Catalyst Guidance
  • Three Solvation Modes
• Architecture
  • Package Overview
  • Data Flow
  • Module Boundaries
  • Device Selection
  • Catalyst And IR Cache
  • Key Design Decisions
  • Extension Points
• Tutorials
  • H2 QPE Validation
  • H2 Resource Estimation
  • Full-One-Electron Fixed-MO Embedding
  • H2 MC Solvation
  • Three-Mode Solvation Comparison
  • Optional Diagnostic Scripts
• Development
  • Environment Setup
  • Testing
  • Linting And Formatting
  • Documentation Workflow
  • Contribution Notes
• Glossary

Reference

• API Reference
  • Package API
  • Core API
  • Interfaces API
  • Solvation API
  • Sampling API
  • Profiling API
  • Utilities API
  • Package Groups

Project Links

• Source repository: https://github.com/yjmaxpayne/q2m3

• Issue tracker: https://github.com/yjmaxpayne/q2m3/issues

• Zenodo archive (concept DOI): https://doi.org/10.5281/zenodo.20114945

Citation

If you use q2m3 in research, please cite the Zenodo archive. The concept DOI 10.5281/zenodo.20114945 always resolves to the latest published release. Use a version-specific DOI (for example 10.5281/zenodo.20114946 for v0.1.1) when you need to reference the exact code behind a result. CITATION.cff in the repository root lists both DOIs and powers GitHub’s “Cite this repository” button.

@software{q2m3_2026,
  title     = {q2m3: A Hybrid Quantum-Classical Framework for QM/MM Simulations},
  author    = {Ye Jun},
  year      = {2026},
  publisher = {Zenodo},
  doi       = {10.5281/zenodo.20114945},
  url       = {https://doi.org/10.5281/zenodo.20114945}
}