clebsch_gordan, a Fortran77 code which evaluates certain coefficient functions used in quantum mechanics.
Mathematica includes the commands ClebschGordan, ThreeJSymbol, and SixJSymbol, which can be used to evaluate the Clebsch Gordon, Wigner 3J and Wigner 6J functions.
The information on this web page is distributed under the MIT license.
clebsch_gordan is available in a Fortran77 version.
slatec, a Fortran90 library which includes routines to evaluate the Clebsch Gordon, Wigner 3J and Wigner 6J functions.
TEST_VALUES, a Fortran77 library which contains a few test values of many functions.