#### 7.8.3 9-j Symbols

Function: double gsl_sf_coupling_9j (int two_ja, int two_jb, int two_jc, int two_jd, int two_je, int two_jf, int two_jg, int two_jh, int two_ji)
Function: int gsl_sf_coupling_9j_e (int two_ja, int two_jb, int two_jc, int two_jd, int two_je, int two_jf, int two_jg, int two_jh, int two_ji, gsl_sf_result * result)

  These routines compute the Wigner 9-j coefficient,

      {ja jb jc
       jd je jf
       jg jh ji}

  where the arguments are given in half-integer units, ja = two_ja/2, ma = two_ma/2, etc.