Program to calculate pure angular momentum coefficients in jj-coupling

A program for computing pure angular momentum coefficients in relativistic atomic structure for any scalar one- and two-particle operator is presented . The program, written in Fortran 90/95 and based on techniques of second q uantization, irreducible tensorial operators, quasispin and the theory of a ngular momentum, is intended to replace existing angular coefficient module s from GRASP92. The new module uses a different decomposition of the coeffi cients as sums of products of pure angular momentum coefficients, which dep end only on the tensor rank of the interaction but not on its details, with effective interaction strengths of specific interactions. This saves memor y and reduces the computational cost of big calculations significantly. (C) 2001 Elsevier Science B.V. All rights reserved.