# New efficient programs to calculate general recoupling coefficients. Part II: Evaluation of a summation formula

## Description

Abstract In Comput. Phys. Commun. 83 (1994) 275, we described a program NJFORMULA to generate a summation formula in terms of 6-j coefficients for a general angular momentum recoupling coefficient. Here we present programs for the second part of the problem, i.e. the numerical computation of a general recoupling coefficient by evaluating the formula generated by the program NJFORMULA. We describe a sequential version NJSUMMATION, written in C, which runs on a range of computers, as well as a parallel ... Title of program: NJSUMMATION, NJSUMPAR Catalogue Id: ADBA_v1_0 Nature of problem A general recoupling coefficient for an arbitrary number of (integer or half-integer) angular momenta can be expressed as a formula consisting of products of 6-j coefficients summed over a certain number of variables. Such a formula can be generated using the program NJFORMULA [1]. The present programs perform the evaluation of a generated formula for given data of angular momenta. Versions of this program held in the CPC repository in Mendeley Data ADBA_v1_0; NJSUMMATION, NJSUMPAR; 10.1016/0010-4655(94)00179-6 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)