Abstract
The profiles of Rydberg series of autoionising resonances predicted by quantum defect theory in the two-channel approximation are investigated as a function of the adjustable parameters. It is shown that there are two distinct types of profile, one of which resembles those parametrised by the Fano formula, while the other does not. It is further shown that both types can be distinguished by a simple test, and experimental examples are given.

This publication has 7 references indexed in Scilit: