1 @cindex coupling coefficients
5 @cindex Wigner coefficients
6 @cindex Racah coefficients
8 The Wigner 3-j, 6-j and 9-j symbols give the coupling coefficients for
9 combined angular momentum vectors. Since the arguments of the standard
10 coupling coefficient functions are integer or half-integer, the
11 arguments of the following functions are, by convention, integers equal
12 to twice the actual spin value. For information on the 3-j coefficients
13 see Abramowitz & Stegun, Section 27.9. The functions described in this
14 section are declared in the header file @file{gsl_sf_coupling.h}.
23 @subsection 3-j Symbols
25 @deftypefun double gsl_sf_coupling_3j (int @var{two_ja}, int @var{two_jb}, int @var{two_jc}, int @var{two_ma}, int @var{two_mb}, int @var{two_mc})
26 @deftypefunx int gsl_sf_coupling_3j_e (int @var{two_ja}, int @var{two_jb}, int @var{two_jc}, int @var{two_ma}, int @var{two_mb}, int @var{two_mc}, gsl_sf_result * @var{result})
27 These routines compute the Wigner 3-j coefficient,
31 \pmatrix{ja & jb & jc\cr
45 where the arguments are given in half-integer units, @math{ja} =
46 @var{two_ja}/2, @math{ma} = @var{two_ma}/2, etc.
47 @comment Exceptional Return Values: GSL_EDOM, GSL_EOVRFLW
52 @subsection 6-j Symbols
54 @deftypefun double gsl_sf_coupling_6j (int @var{two_ja}, int @var{two_jb}, int @var{two_jc}, int @var{two_jd}, int @var{two_je}, int @var{two_jf})
55 @deftypefunx int gsl_sf_coupling_6j_e (int @var{two_ja}, int @var{two_jb}, int @var{two_jc}, int @var{two_jd}, int @var{two_je}, int @var{two_jf}, gsl_sf_result * @var{result})
56 These routines compute the Wigner 6-j coefficient,
60 \left\{\matrix{ja & jb & jc\cr
61 jd & je & jf\cr}\right\}
74 where the arguments are given in half-integer units, @math{ja} =
75 @var{two_ja}/2, @math{ma} = @var{two_ma}/2, etc.
76 @comment Exceptional Return Values: GSL_EDOM, GSL_EOVRFLW
81 @subsection 9-j Symbols
83 @deftypefun double gsl_sf_coupling_9j (int @var{two_ja}, int @var{two_jb}, int @var{two_jc}, int @var{two_jd}, int @var{two_je}, int @var{two_jf}, int @var{two_jg}, int @var{two_jh}, int @var{two_ji})
84 @deftypefunx int gsl_sf_coupling_9j_e (int @var{two_ja}, int @var{two_jb}, int @var{two_jc}, int @var{two_jd}, int @var{two_je}, int @var{two_jf}, int @var{two_jg}, int @var{two_jh}, int @var{two_ji}, gsl_sf_result * @var{result})
85 These routines compute the Wigner 9-j coefficient,
89 \left\{\matrix{ja & jb & jc\cr
91 jg & jh & ji\cr}\right\}
105 where the arguments are given in half-integer units, @math{ja} =
106 @var{two_ja}/2, @math{ma} = @var{two_ma}/2, etc.
107 @comment Exceptional Return Values: GSL_EDOM, GSL_EOVRFLW