Calculation of general recoupling coefficients using graphical methods Original Research Article

A new program to generate a summation in terms of 6-j coefficients for a general angular momentum recoupling coefficient is described. This algorithm makes use of the graphical techniques as developed by Yutsis, Levinson and Vanagas Attention is paid to providing an appropriate data structure for the graph representing a general recoupling coefficient, and to reducing the coefficient to a summation formula with a minimum number of summation variables. Our results are compared to those of Bar-Shalom and Klapisch, who developed the program NJGRAF for the same purpose, also using graphical methods.