Uploaded to Maxima by Example webpage:
A Clebsch-Gordan Coefficient Package for Maxima
Contains (not very efficient) Maxima code for
Wigner vector coupling coefficients
(Clebsch-Gordan coefficients) cj (j1,j2,j3,m1,m2,m3)
and the simply related Wigner 3j coefficients
threej (j1,j2,j3,m1,m2,m3), both for explicit
integer and half-integer arguments only.
--clebsch.mac : Oct. 22, 2010, Maxima 5.21.1
Ted Woollett
http://www.csulb.edu/~woollett
p.s. A more efficient code for the above, as well
as the Wigner 6j and 9j, would be a good contribution
to Maxima.