C++ templated library for Wigner 3j, 6j, 9j symbols and Gaunt coefficients
This library is for the numerical computation of special functions appearing in angular monentum coupling theory:
- Wigner 3-j symbol (Wikipedia, Wolfarm)
- Wigner 6-j symbol (Wikipedia, Wolfarm)
- Wigner 9-j symbol (Wikipedia, Wolfarm)
- Gaunt coefficient
Wigner 3-j and 6-j symbols and Gaunt coefficiens are calculated using the three-term recurrence relations originally derived by Schulten and Gordon [^Schulten1975] and improved to avoid overflows by Luscombe and Luban [^Luscombe1998].
You need a newer C++ compiler that supports the C++11 standard, such as GCC (>= 4.8.0) and Clang (>= 3.2).
This library depends only C++ standard libraries: no external library is required.
For building unit tests, Catch testing framework is required. This step is optional.
wigner-cpp is a header only library. You can use it by including header files
under wigner directory.
See, example program in example directory.
Copyright (c) 2016 Hidekazu Ikeno
Released under the MIT license
[Schulten1975]: Klaus Schulten and Roy G. Gordon, "Exact recursive evaluation of 3j and 6j-coefficients for quantum-mechanical coupling of angular J momenta," J. Math. Phys. 16, pp 1961-1970 (1975).
[Luscombe1998]: James H. Luscombe and Marshall Luban, "Simplified recursive algorithm for Wigner 3j and 6j symbols," Phys. Rev. E 57, pp. 7274-7277 (1998).