# quantumlib/OpenFermion

Python package for compiling and analyzing quantum algorithms to simulate electronic structures.

Repository: https://github.com/quantumlib/OpenFermion
Canonical: https://ross.abutalabs.com/products/openfermion
Homepage: https://quantumai.google/openfermion
Language: Python
License: Apache-2.0
License Family: permissive
Topics: quantum-computing, quantum-chemistry, quantum-algorithms, quantum-programming-language, electronic-structure, algorithms, cirq, google-quantum, high-performance, python, quantum, quantum-information, quantum-simulation, sdk, colab, jupyter-notebook, quantum-programming, simulation, fermion, quantum-circuit
Last push: 2026-08-24T18:24:49+00:00

## Health v2 (maintenance only)
Score: 89/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 69, longevity 100
- inputs: {"age_days": 3268, "days_push": 9, "days_rel": 47, "gap_med": 114, "n_releases_24m": 4}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1731, forks 432 (observed 2026-08-28T04:05:28.730011+00:00)

## What it is
OpenFermion is an open-source Python library for compiling and analyzing quantum algorithms that simulate fermionic systems, including quantum chemistry. It provides data structures and tools for representing and manipulating fermionic and qubit Hamiltonians, with a plugin ecosystem for circuit simulation and classical electronic structure calculations.

## Use cases
- simulate fermionic systems on quantum computers
- translate quantum chemistry problems into quantum circuits
- build and manipulate fermionic and qubit Hamiltonians
- compute molecular ground state energies with quantum algorithms
- model Hubbard models and lattice Hamiltonians
- prepare electronic structure calculations for quantum hardware
- research quantum algorithms for materials science

## When to choose
- you need to simulate fermionic or quantum chemistry systems on quantum hardware or simulators
- you want efficient data structures for fermionic operators and Hamiltonians
- you work with Cirq or Google Quantum AI tooling
- you need a plugin-based ecosystem combining chemistry and quantum circuit compilation

## When to avoid
- you only need classical computational chemistry without quantum computing
- you need a general-purpose quantum circuit framework rather than chemistry-focused tools
- you require Windows-native support for electronic structure plugins without Docker

## Facets
- artifact type: library
- maturity: active
- function: simulation, sdk, compiler, math
- domain: quantum-computing, chemistry, machine-learning
- platform: python, windows
- tags: quantum-chemistry, fermionic-systems, electronic-structure, quantum-circuits, cirq, hamiltonian-simulation, quantum-simulation, algorithms, linux, macos, docker

## Member repositories
- quantumlib/OpenFermion (main) score 89

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:28.730011+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:31:43.747917+00:00, confidence not recorded.
  - readme: https://github.com/quantumlib/OpenFermion (fetched 2026-08-28T04:05:28.730011+00:00, sha 337c845b0566)
  - homepage: https://quantumai.google/openfermion (fetched 2026-08-29T11:08:32.387045+00:00, sha 01c17e686f7f)
  - site_page: https://quantumai.google/cirq (fetched 2026-08-29T11:08:32.396049+00:00, sha b886c740d077)
- Data as of 2026-08-30T08:39:29.467469+00:00.