Parallel computation of recoupling coefficients using transputers

Abstract
Parallel algorithms for the computation of angular momentum recoupling coefficients are discussed. The first situation where parallelisation has a remarkable impact is for the computation of the 9-j coefficient. A parallel program in C for the numerical calculation of the 9-j coefficient is presented and compared with sequential programs in C.

Title of program: NINEJPAR
Catalogue Id: ACJE_v1_0

Nature of problem
A parallel program calculates the 9-j coefficient (also called the ls-jj transformation coefficient) using the single sum over the product of three 6-j coefficients formula. This coefficient arises in the recoupl- ing of four angular momenta, which can be coupled either using the Russell-Saunders scheme or the jj-coupling scheme. It is of fundamental importance in the evaluation of matrix elements which occur in nuclear, atomic and molecular physics.

Versions of this program held in the CPC repository in Mendeley Data
ACJE_v1_0; NINEJPAR; 10.1016/0010-4655(92)90015-Q

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)

摘要
本文探讨了角动量重组系数的并行计算算法。并行化对计算9-j系数的影响尤为显著。本文提出并展示了一个用于数值计算9-j系数的C语言并行程序，并与C语言的顺序程序进行了比较。
程序标题：NINEJPAR
目录编号：ACJE_v1_0
问题性质
本并行程序通过单和积方法计算9-j系数（亦称ls-jj变换系数）。该系数在四个角动量的重组过程中产生，可使用Russell-Saunders方案或jj耦合方案进行耦合。在核、原子和分子物理中，该系数在矩阵元评估中具有根本性的重要性。
Mendeley数据中CPC仓库保存的此程序版本
ACJE_v1_0; NINEJPAR; 10.1016/0010-4655(92)90015-Q
此程序已从贝尔法斯特女王大学（1969-2019年）保存的CPC程序库中导入。