Rydberg equation

This pieture is that deseribed by the BO approximation. Of eourse, one should expeet large eorreetions to sueh a model for eleetronie states in whieh loosely held eleetrons exist. For example, in moleeular Rydberg states and in anions, where the outer valenee eleetrons are bound by a fraetion of an eleetron volt, the natural orbit frequeneies of these eleetrons are not mueh faster (if at all) than vibrational frequeneies. In sueh eases, signifieant breakdown of the BO pieture is to be expeeted.  [c.65]

Computational chemistry using the PC (2003) -- [ c.76 ]