Abstract
In calculating the static Stark effect, when limiting the number of perturbing levels to those with the same principal quantum number, one introduces negligible errors on the peak separation between the allowed and forbidden lines. On the other hand, one may affect the profile in the region of the forbidden component. In the case of CsI(6G-5D), it is shown, by calculating the ionic profiles, that this limitation contributes to overestimate the maximum intensity of the (6G-5D) forbidden line and to reduce the intensity between the allowed (6F-5D) and the forbidden (6G-5D) lines.