The authors describe a numerical model developed for the argon neutral system. The major question for non-hydrogenlike systems is which electron-collision cross-section between excited states have to be used, since theoretical or measured values are in general not available. Another severe problem, specific to the numerical approach, is how many states or groups have to be taken into account to get a reliable model. Up till now, the specific results of several CR models for the argon neutral system were unsatisfactory and disagree with each other. The authors present the r/sup 1/(4p) coefficient as a function of the electron density n/sub e
