# SPDX-License-Identifier: BSD-3-Clause
# Copyright (c) 2026 Susi Lehtola
cff-version: 1.2.0
message: "If you use libwignernj in published work, please cite the paper under \"preferred-citation\" below."
title: libwignernj
abstract: >-
  Exact evaluation of Wigner 3j, 6j, and 9j symbols, Clebsch-Gordan
  coefficients, Racah W-coefficients, Fano X-coefficients, and Gaunt
  coefficients in C99, with C++, Fortran 90, and Python bindings.  All
  intermediate arithmetic is exact integer arithmetic in a
  prime-factorization representation; floating-point conversion happens
  only at the final step, so results are correct to the last
  representable bit of the chosen output precision.
type: software
authors:
  - given-names: Susi
    family-names: Lehtola
    orcid: "https://orcid.org/0000-0001-6296-8103"
    email: susilehtola@gmail.com
version: 0.8.0
date-released: "2026-06-29"
license: BSD-3-Clause
repository-code: "https://github.com/susilehtola/libwignernj"
url: "https://github.com/susilehtola/libwignernj"
keywords:
  - Wigner symbols
  - Clebsch-Gordan coefficients
  - Racah coefficients
  - Gaunt coefficients
  - angular momentum
  - exact arithmetic
preferred-citation:
  type: article
  title: "libwignernj: a reusable C/C++/Fortran/Python library for exact Wigner symbols and related coefficients"
  authors:
    - given-names: Susi
      family-names: Lehtola
      orcid: "https://orcid.org/0000-0001-6296-8103"
  year: 2026
  doi: 10.48550/arXiv.2605.06634
  url: "https://arxiv.org/abs/2605.06634"
  identifiers:
    - type: other
      value: "arXiv:2605.06634"
      description: arXiv identifier
