Knowledge Bank

It is well known that Rydberg-Klein-Rees (RKR) potential curves often display irregular behavior as the dissociation limit is approached, particularly on the inner wall. This irregular behavior is not found in, e.g., ab initio potentials and is an artifact of the RKR method. In particular, the $Gv$ and $Bv$ input for v $\to$ dissociation are (a) experimentally relatively uncertain, (b) often dependent primarily on the long-range region near $Rv+$ and not on the inner wall near $Rv-$, and (c) often seriously perturbed in a diffuse (i.e., multistate and/or continuum) sense. Because of the frequent lack of sensitivity to the inner wall in the RKR input, other (new) methods such as discrete analogs of the behavior of the Condon Reflection method or the direct construction of the function $\partial V/\partial R$ may be more useful in obtaining a reliable inner wall.