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Manuscript Title: A program for calculating relativistic elastic electron-atom collision data.
Authors: A.C. Yates
Program title: A SCAT
Catalogue identifier: ACQX_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 2(1971)175
Programming language: Fortran.
Computer: CDC 6600.
Operating system: SCOPE 3.3.
RAM: 20K words
Word size: 60
Keywords: Atomic physics, Scattering, Electrons, Relativistic, Partial-waves, Spin-polarization, Numerov.
Classification: 2.4.

Nature of problem:
The program calculates angular distributions (differential cross sections) and spin-polarization distributions of electrons scattered elastically by atomic targets within the framework of the static field approximation, by solving the radial Dirac equations.

Solution method:
The radial Dirac equations are cast into Schrodinger form, and the resulting second-order differential equation is solved by using tehe modified form of the Numerov algorithm. The partial-wave series are then summed directly.

Restrictions:
As written, the program handles any scalar potential written as a sum of Yukawa terms, but is easily modified to treat other functional forms, or numerical tables.

Running time:
The test run for Z=7, at 500 ev requireds 25 partial waves run takes 17 s to execute on the CDC 6600.