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Manuscript Title: Fine structure cross sections from reactance matrices: a more versatile development of the program JAJOM.
Authors: H.E. Saraph
Program title: JAJOMPRE
Catalogue identifier: AAGJ_v2_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 15(1978)247
Programming language: Fortran.
Computer: IBM 360/65.
Operating system: OS 360, SCOPE 3.4.
RAM: 90K words
Word size: 8
Keywords: Atomic physics, Electron-atom, Scattering, Reactance matrix, Pair coupling, Collision strength.
Classification: 2.4.

Nature of problem:
Results from calculations with LS-coupled wave functions (reactance matrices and term coupling coefficients) are used to compute collision strengths for transitions between fine structure levels.

Solution method:
The input is carefully checked. The algebraic transformation uses Racah algebra, the coefficients are computed as required. An optional further transformation to allow for intermediate coupling in the target requires term coupling coefficients to be supplied by the user. The collision strengths are computed using either of two formulae, corresponding to weak or strong coupling respectively.

It is not recommended to use the program for angular momenta greater than about 20. But adaptations are possible by replacing the Racah algebra subroutines. We discuss addition of contributions from high angular momenta using approximate methods. For problems with a large number of target levels the execution time can become large; a comment card in MAIN points to a place where a RESTART procedure can conveniently be inserted.

Unusual features:
This version of JAJOM is very flexible. Using the preprocessor included with this deck machine dependent features, array lengths, and mode of operation are all inserted according to the user's requirements.

Running time:
We give two sets of sample runs, which took 12 and 27s respectively on the IBM 360/65.