New heuristic approach to the calculation of general recoupling coefficients

2019-12-06T07:32:26Z (GMT) by D Van Dyck V Fack
Abstract General angular momentum recoupling coefficients can be expressed as a summation formula over products of 6-j coefficients. Yutsis, Levinson and Vanagas developed graphical techniques for representing the general recoupling coefficient as a cubic graph and they describe a set of reduction rules on such a graph which allow a stepwise generation of the corresponding summation formula. In this paper we present a new heuristic approach to earlier reduction algorithms based on these techniques. In... Title of program: CycleCostAlgorithm, GYutsis Catalogue Id: ADRM_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 GYutsis (with a graphical user front end) or CycleCostAlgorithm (with a text-mode user front end). Versions of this program held in the CPC repository in Mendeley Data ADRM_v1_0; CycleCostAlgorithm, GYutsis; 10.1016/S0010-4655(02)00733-6 ADRM_v2_0; GYutsis: VAN DYCK, FACK; 10.1016/S0010-4655(03)00280-7 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)