Susi Lehtola

libwignernj: A reusable C/C++/Fortran/Python library for exact Wigner symbols and related coefficients

We describe libwignernj, a freely available, BSD-licensed library that evaluates Wigner 3j, 6j, and 9j symbols, Clebsch--Gordan, Racah $W$, and Fano $X$ coefficients, and Gaunt coefficients over both complex and real spherical harmonics in standards-compliant C99. libwignernj rep...